Hello everybody!
As some of you know from my add in the for sale section, I just picked up a neglected 2004 GS500F from a hack artist. I paid way too much, but I just love to fix broken things. I am an engineer by training, but a tinkerer at heart. I bought this one as a winter project. I have another 04F that I picked up this winter and it needed a motor so I put in a good used one from eBay. So now I have two 04Fs and at least one and possibly both will need to go to make way for new future projects.
Picture of the Yellow Bird (guess that'll be the bikes name from now on) below. Note the missing muffler, I don't want to know how loud it will be without it. I plan to put a stock exhaust on it.
The bottom two pictures show the carb in the state it was in when I got the bike. Can anyone point out the problems? (And no it's not the Pods though I do plan to change those out.) He said it ran before he put it away, I'm thinking he was fibbing a bit.
After a bit of carb cleaning and wiring issues I got the bike to fire up. Still doesn't idle right, but I need to get a new float bowl gasket for the left carb and drill out the fuel screws to richen it up a bit.
PS anyone have any good ideas for getting broken exhaust bolts out of the head? Fortunately they sheared with about 1/2 inch poking out so I can still get something on them, just hoping to avoid pulling the head.
I'm always excited to see a new project thread on the forum! Especially one where a GS gets rescued!
I don't have any tips on getting the broken exhaust bolts out... but I can say that per advice from this forum, I replaced the stock bolts with studs and nuts.
Looking forward to updates :cheers:
I think you may have to bite the bullet and pull the heads to get the stud out. Too little space to work in. You could try ( if the thread exists on the remains of the stud) threading two pieces of square stainless 5mm and locking them together them turning them out with the inner one. Seen a rod welded to a stud at right angles but they tend to snap then the stud remains get harder to work with. Good luck with it. You could always get another head. Clean it up and mod it and change it over. I note you are in the US so getting a second hand head should be cheap and easy.
I found with my 07 project bike that the carbs are extremely finniky and had to clean then a few times before they were OK.
About to put a electric fuel pump/shutoff on mine to bypass the ridiculous fuel plumbing stock. I suspect that is part of the carb contamination problem.
Did you try running it with no air filters? The idle problem may very well be those pod filters. They likely have a "lip" on the inside that covers the little teeny orifices where air comes in for idle. I'd think it can't idle right at all with the pod filters like that (I have a pair!!). Your only choice would be to try to get it to "idle" by opening the throttle plate stop and getting air over the mid jet at "idle" which is choppy at best and more likely 3K+ before it'll be steady. That's how to make a three-circuit carb into a two-circuit carb.
Anyway, get a stock airbox on there and then start thinking about tuning.
You certainly need to drill the pilot adjuster covers and pull them but you won't be able to get the idle mixture right without rejetting. Upsize the pilot jet by one (I think in an '04 that's a #20) and maybe shim the needle with one washer to beef up the mixture on main? IDK much about these '01+ carbs. But I would highly recommend doing the procedure outlined in my blog post (https://joshkarnes.blogspot.com/2017/09/fixing-common-gs500-carburetor-issues.html) for refreshing the carbs with of course adjustments for the Mk2 carbs.
Mr. 72,
I am very familiar with your blog post about carburetor overhaul. I've read it a couple of times. Really good information. I ended up reading your whole blog (at least all those labelled as motorcycle posts). I liked the writing so much that I am tempted to look up a bit of your Si-Fi work to see if I like it too. I am on the hunt for a stock airbox as well. For now I just wanted to get it running and cleaned up before I started on the fine tuning.
Thanks for the feedback I was hoping you'd chime in because you usually look at things in a level headed manner that makes sense.
The current jetting is stock which is 130/60/17.5 which tells me the previous owner knew nothing about needing to rejet when changing things like intake and exhaust. I am almost happy to have to drill out the air screw because it means no newbie was in there messing things up before me.
Now that I have it running I'll check the valve clearances.
PS. Did you notice the float bowls were installed reversed (how are you supposed to do a float bowl fuel level check like that?) as well as the caps being installed backwards....the white diaphragm plastic doohickeys should be pointing the other direction.
Ken
Quote from: Kenner on January 09, 2018, 01:26:47 PM
Mr. 72,
I am very familiar with your blog post about carburetor overhaul. I've read it a couple of times. Really good information. I ended up reading your whole blog (at least all those labelled as motorcycle posts). I liked the writing so much that I am tempted to look up a bit of your Si-Fi work to see if I like it too.
:thumb:
music to my ears!
:)
[you know my first book is free on Smashwords... fast reader will knock it out in 4 hours]
Now, on to practical matters:
You can set up the idle with no air filters. The air filter doesn't affect idle mixture at all. With the throttle plate [almost entirely] closed, the bike will idle with air drawn in through the holes near the bottom of the rim of the carburetor inlet. There's not enough vacuum to affect the "mixture" on the main jet.
With a #20 pilot jet you should be able to dial in the idle mixture just fine. Problem is going to become getting the bike fully warmed with it running with the pod filters, since riding it off idle is going to be a challenge. It probably runs like dog poo and is at risk of burning valves with stock jetting and those air filters. And like I say it won't idle right with those filters anyway. So you might be in a catch-22 until you can get your hands on a stock airbox. Might as well get a handful of o-rings and swap the intake boot o-rings while the carbs are not on the bike.
Quote
Now that I have it running I'll check the valve clearances.
I'd do a compression check too if you can, since who knows how long it was run way lean with those pods and the risk of burning valves is >0 in that state.
Quote
PS. Did you notice the float bowls were installed reversed (how are you supposed to do a float bowl fuel level check like that?) as well as the caps being installed backwards....the white diaphragm plastic doohickeys should be pointing the other direction.
nah. I saw the pods and jumped on that. Who knows what other issues backward float bowls cause. Maybe none. I know I have inadvertently put one on backwards on my bike before, but never both and put them on the bike that way :) They fit both ways. My guess is they function both ways. My guess is that on a single-carb bike it doesn't matter which way they run, just one or the other way to afford access to the bowl tap. But that's just a guess. I don't know this for sure.
And FWIW in case you didn't notice already, everything I say is from my personal experience and a bit of calculating on my part. I'm not an authority. I'm just a tinkerer with a year's head start on you.
Josh - that's why you can't sell your GS and leave the forum. We need you and your smarts!!! :cheers:
Kenner - I don't think the orientation of the carb bottoms or the white discs affects how the bike runs at all. There are a lot of carb parts that can go in either orientation, I suppose to save on manufacturing costs. With some futzing and fiddling, looks like you can swap one carb body to the other side.
Use the 'heat spanner' on those seized studs, - A soak in CRC or similar - the longer the better, - a few sharp taps on the stud ends with a hammer to jar free the corrosion in the thread, then very carefully, with heat applied around the zorst port areas, see if you can ease the studs back and forward a few degrees with molegrips or stud remover. No use straining them too much by trying to turn them too far, you'll shear them, once they move a few degrees, then they'll come. But don't rush it, work them a little at a time, using CRC and heat.
+1 for soaking them and heat. If you can weld a nut on the broken bit, often the heat of welding is enough to help loosen them. If you do weld on a nut you can try turning them whilst gently tapping them with a hammer too!
Endopotential,
I believe your right that the orientation doesn't/won't affect how it runs. I was able to unscrew the caps and flip them both top and bottom. What it shows me is that a previous owner was such a newbie that he/she didn't bother to look up how to properly reassemble them.
This evening I had a bit of fun in the garage. I was able to double nut the two sheared studs, but they still didn't want to come free. I sprayed them with penetrating oil yesterday and hit them with a small torch today before trying to loosen them, but I couldn't jam one nut tight enough into the other to grip it strong enough to extract it.
Next I center punched the studs and drilled a small 3/32 hole all the way through them. I then enlarged the center hole to 1/8. This allowed me to spray penetrating oil up inside the head and hopefully work on the corrosion from the inside. Also the hole slightly weakens the bolt so it may help it give way. Tomorrow I'll try the double nut again. If that doesn't work I do have a Lincoln buzzbox 220 welder, but I fear to weld to an engine on a frame since the current may pass thru bearings or other things and possibly arc and score them. It really should be done with an acetylene torch, but I don't have one nor do I know how to use one. If the double nut doesn't work tomorrow I may just vice grip directly to the stud and try to wiggle it a bit.
I also played with the carbs a little more today. I need to order a couple of rebuild kits and give them the once over since at least one of the fuel valves is not sealing. I've had decent luck with the K&L kits from eBay.
One trick to share (as shown in the bottom image)is if one of those "cheese grade" JIS screws is stripped out, you can usually get it functional again by clamping on the screw in a vice and hitting the head with a hammer. They often fail due to a phillips screw driver caming out of the slot and bending the corners of the srew up. Pounding them back down usually makes it functional again. And remember Japanese bikes use JIS screws not Phillips screws. Save yourself some grief and buy a JIS set.
Ken
Sub'd!
Quote from: Kenner on January 09, 2018, 11:01:13 PM
If that doesn't work I do have a Lincoln buzzbox 220 welder, but I fear to weld to an engine on a frame since the current may pass thru bearings or other things and possibly arc and score them.
Ken
That isn't an issue, I have welded to several engines - including weld aluminum onto a savage motor. No issue welding a bearing shut, ever.
Cool.
Buddha.
Yellow Bird --> 2 Kenner --> 0
I put caution to the wind and trusted Buddha's suggestion and welded nuts to the studs. Then I hit it with heat from a torch and smacked the stud with a hammer to try to break it free but to no avail, unfortunately, they still did not come free. All that happened was the screw sheared again at the next thread in beyond the weld. I sprayed a bit more penetrating oil and I'll let it sit for another day and try again. I have at least 2 more tries worth of stud. If that doesn't work I have backup plans 1 and 2. Plan 1 is I ordered a set of left hand cobalt drill bits which I will use to gradually enlarge the hole until either the stud comes out, or I have it large enough to run a tap thru to clean out the broken stud. Fortunately my pilot holes are centered pretty darn good so I am not too worried about eating into the aluminum threads with a drill bit. Plan 2 is use acid to eat out the bolt. I will drill it out until the holes are bigger and fill them with acid and let it do its thing. I learned about this trick from a website (named http://www.dansmc.com/) where an old school motorcycle mechanic from Idaho filled his winters with creating a free online motorcycle repair course. Lots of good stuff there. You should check it out. Namely his post about dissolving broken bits with acid http://www.dansmc.com/acid.htm
Now is just the waiting game. I have carb parts coming, I have the left hand drill set coming, and I have penetrating oil (hopefully) working its way under the stud screw.
Something to contemplate. The 2 bolts that sheared were both the inner bolts. The outer ones came out just fine. Is there a different stress or failure mode specific to the inner bolts to cause them to corrode in more than the outer ones? If any have sheared on you were they inner or outer?
Ken
Top pic nut welded in place.
Middle pic nuts sheared off.
Bottom pic nuts showing sheared stud inside.
Stainless bolts to replace them with aluminium grease should help ensure it doesn't happen again and just happen to look good as well.
Acid will eat the porus aluminum crap 100X as fast as the work and heat hardened steel bolt. Do not use acid, you're better off drilling and ez outing it.
I have done that to another bike and tapped the eaten up threads to a slightly larger SAE size.
Helps to take off the front suspension and crank the bike to the height with a winch or a tie down thrown over a tree branch or from the shop ceiling beam or something - it may be needed to where you can put some force on it when drilling the bolt. I'm trying to remember ho I cranked it up.
Cool.
Buddha.
Quote from: The Buddha on January 12, 2018, 01:23:37 PM
Acid will eat the porus aluminum crap 100X as fast as the work and heat hardened steel bolt.
how porous or how hard the material is has nothing to do with whether acid will dissolve it.
Sulfuric acid will dissolve the steel bolt readily while the oxide layer on the surface of the aluminum will substantially limit how much the acid can act on the aluminum. The ability of aluminum oxide layer that forms on aluminum in ordinary atmosphere to protect the aluminum from corrosion is a big reason for using aluminum for anything, it is very corrosion-resistant.
That aluminum oxide is aka "ceramic" and is very hard and corrosion resistant.
Just don't use hydrochloric acid. From what I read to dissolve steel and not aluminum, you should use 15% sulfuric acid.
OK well I've seen massive holes in cars and bikes near the battery so sulphuric acid will make mince meat out of the steel.
The engine is made of a mix of mystery metal, most of which is aluminum, so you may be mostly OK there too.
Good one mr72 thanks.
Cool.
buddha.
Quote from: The Buddha on January 12, 2018, 02:03:48 PM
OK well I've seen massive holes in cars and bikes near the battery so sulphuric acid will make mince meat out of the steel.
That it will. And hydrochloric acid will to. Or even vinegar (acetic acid), but only much more slowly.
Quote
The engine is made of a mix of mystery metal, most of which is aluminum, so you may be mostly OK there too.
Yeah it's just an aluminum alloy. IDK if there's a steel cylinder liner. Also the valves are steel and there are other steel parts in there (the rings!) so I'd personally avoid getting any acid in/near the cylinder head.
Quote
Good one mr72 thanks.
Hey, you know someone had to pay attention in Chemistry class. I'm always down for hanging on to what is most likely useless information just for occasions like this.
Yellow Bird --> 3 Kenner --> 0
I tried welding nuts again and all it did was shear it shorter. So I went about drilling to holes a little bigger. I have them at 5/32 now and I used a small syringe to put a little bit of battery (i.e. sulfuric) acid down the holes.
If you follow the link I posted above the author explains (as did Mr72) that sulfuric acid will dissolve steel and leave the aluminum unscathed (muriatic acid, on the other hand, will dissolve aluminum and leave steel alone). You just need the right acid for the job.
I chose not to go with the left handed drill because I figured I would just break my bit trying to drill out the bolt since it is corroded in big time. Also, since it's a blind hole I was hoping the acid would fill the hole and free up the studs a little so an easy out can get purchase and remove it after it has dissolved a little.
If it comes out I'll clean the threads with a tap and install studs and nuts. If that still doesn't work I'll drill it larger and install a time-sert thread repair coil (I like them better than helicoils because they are solid with threads inside and out rather than a spring-like threaded coil).
I'll report on how well the acid did later.
Ken
Top pic, I steeply angled the bike so the acid would flow to the bottom of the hole.
Bottom pic. I sealed the hole with double sided tacky tape then poked a hole in it and squeezed in a little acid.
Quote from: Kenner on January 12, 2018, 03:05:32 PM
If you follow the link I posted above the author explains (as did Mr72) that sulfuric acid will dissolve steel and leave the aluminum unscathed (muriatic acid, on the other hand, will dissolve aluminum and leave steel alone). You just need the right acid for the job.
Careful. Muriatic (hydrochoric) acid will indeed munch steel like no tomorrow. BTDT.
By the way, muriatic acid, which is a low-concentration HCl available at pool supply stores, will also dissolve concrete pretty readily if you ever find yourself having to dig out a fence post footing. WOT I know.
Muriatic acid will eat aluminum and aluminum based alloys a lot faster than it will eat clean steel. It will eat rusted metal very very fast.
If your problem is that there is rust and heat that's gooped up in there and threads etc etc have shards of rusty metal preventing it from getting out, yea muriatic acid will get that eaten, but if you have cross thread type madness, you're gonna eat the aluminum fast.
On my first tank kreeming experience, I blew a hole in the petcock overnight trying to get rust out of the tank. Trust me, aluminum based alloy will go fast when you hit it with muriatic acid.
Cool.
Buddha.
To save my pride I think I'm going to quit keeping score since the Yellow Bird is running up the score.
So turns out my acid trial didn't work out. It was probably due to using used acid from a dead old battery and not fresh new acid. I resorted to continuing to drill the studs out. I drilled them a tad oversize for an m8X1.25 but that was to clear out more of the corroded-in bolt from the holes. I started with a 17/64 (0.263) but then went up one size to 9/32 (0.281) .... according to the machinery handbook the hole should be 6.8mm (0.268") for this tap.
I then recut the threads with an m8X1.25 HSS tap. The studs will screw in, but the threads feel a little weak. I am at a crossroads on what to do next. Since I am changing the configuration to be studs instead of screws I have a few options. First, I could slather the studs in JB weld and then thread them into the holes and let it cure. Since the studs won't be spinning to put the exhaust back on this should work fine as it just needs to mostly resist the tensile force the nut will apply to the flange. I am tempted to go this route because if it doesn't work I can always drill it larger and add the insert, once drilled larger there is really no going back (easy to remove material but very difficult to put it back).
The second option is to drill it out larger for a threaded insert. I have a set of E-Z lock threaded inserts coming from Amazon, but I am deciding whether I want to use them. They have an m12X1.75 outer thread. This requires drilling a 10.8mm (0.425") hole and the threads themselves have a major diameter of 0.475". I am concerned going this route because of how large the holes need to be drilled and whether it will weaken the head or encroach into the exhaust chamber. It appears there is enough aluminum meat but it'll be close. Has anyone gone this route?
The third option would be to oversize the bolts to the next thread size which is m9X1.25. I am very reluctant to do this because I hate having mis-matched hardware. It always feels like such a hack job if you do it that way.
I did take the opportunity to check the valve clearances and the compression on the Yellow Bird this weekend.
Left Exhaust 0.003" Right Exhaust 0.004"
Left Intake 0.002" Right Intake 0.002"
Left Compression 120 psi Right Compression 120 psi
(edit: now that I have the bike running I redid the compression test after getting the engine to full operating temperature.)
(Left Compression hot 128 psi Right Compression hot 129 psi)
When I first measured the LI it was less than 0.0015 but unfortunately I didn't have a 0.001 feeler gauge (0.0015 was my smallest). The shim was stamped 245 and it measured 0.0966" with a micrometer. I pulled all the shims on my spare motor to see if one was small enough, but they were all too large at (0.105"X2 and 0.1104"X2). I resorted to sanding the shim down to 0.096" and reinstalled it. After that I could get my 0.002 feeler gauge under it which tells me it was just barely under my smallest feeler gauge so it was likely still within spec before the sanding. I will tell you that sanding 6 ten thousands of an inch off the shim took about 15-20 minutes. Those shims are made of hard material.
The compression is a little low according to the manual, but it also said to get the bike to operating temperature before performing the check. I did the check cold since the carbs are still off the bike waiting for rebuild kits.
Ken
Top pick -> Two inner threaded holes cleaned up after drilling out sheared screws.
Bottom pick -> Studs I will use to replace screws. These came from a 98-02 chevy cavalier exhaust manifold. I just happen to have a half dozen of them laying around from a repair I did on my natural gas cavalier.
Good job getting the bolts out! And ditto that sanding the shim, although if it were me I think I would not trust that I could sand it and have it remain flat within 0.001", I'd be afraid it'd rotate on me.
Your compression is low enough that it may cause you problems down the line. Heck, you have it apart this far, how hard is it to pull the head and jug, hone the cylinders and put in some rings?
Anyway, about your options on the exhaust studs, I agree with you that using the existing holes/threads is the least risky way to do it but I wouldn't use JB Weld because of a lot of reasons, not the least of which is that if you manage to get threads cut in it without it just flaking off it still only has 500F temperature rating which is not half of what I'd want for an exhaust stud. OTOH I think your existing threads are probably sufficient if you use a high-temp threadlocker. Loctite makes one rated for 650F and these guys (http://www.cotronics.com/vo/cotr/rm_threadlockers.htm) have one rated to 2100F if you can find it. I'd probably just Amazon-Prime the Loctite and put the stud in with that, then make dang sure I never over-torqued it.
IMHO. And that's a heck of a lot easier than trying to fill and re-tap the hole. BTDT, never seen it work right, always more trouble than it was worth... well except one time when I packed a broken threaded hole in a magnesium bicycle fork (disc brake stud) with plastic steel putty and then drilled and tapped it like it was brand new material, but that's not a temperature sensitive application and I had the PSP on hand (it's very expensive, like $80). And that was an M5. Whole different animal. If you have salvageable threads then threadlocker seems like the way to go here.
If you had the head off this might be a good time to try aluminum brazing ... in theory you could just coat the threads and reduce the holes a little then re-tap, or use this method, which sounds dodgy but maybe if you chased the threads after... (https://www.aluminumrepair.com/thread-repair/). Maybe when you have to take it all down again in a couple of months for a top end rebuild to fix that 120psi compression ;)
had a look ate that material and it looks the go actually. Attached video of a use and the joint is stringer than the base. For this job could be a real alternative. BTW alu-brite should clean the hole very well then wash it with lots of water before use. CAREFUL of alubrite as it contains Hydroflouric acid which makes the other halogen acids look like pussies and is not at all good for you skin and body. It will absorb straight through the skin. GLOVES! For the bolt coat it with moly( very thin) or teflon spray ( temp stable) and the bolt should turn out very easily.
https://www.youtube.com/watch?v=RCrixbXz4rc
I've been back at it in the garage. I decided instead of trying to hodge podge something together for the exhaust bolts that I would just repair them properly. I chose to go with a Time-Sert m8X1.25 kit for this repair. While Time-Sert is on the expensive end (the kit cost $73 US) in the end it was worth it. You get a fantastic repair that in this instance is stronger than the original because you are threading the studs in and out of a steel insert instead of aluminum threads (yes the insert is threaded into the aluminum threads, but once in it stays put and from my experience threads generally strip when tightening).
Another thing I like about the Time-Sert kit is that the inserts are very thin. They are only 0.372" diameter where an m8 bolt measures 0.307". The other inserts I was looking into were an m12X1.75 on the outer threads which has a diameter of 0.472" (these are much cheaper and can be installed with a normally available tap where the Time Sert tap size is non-standard). This means the holes would've been a tenth of an inch larger to fit the generic insert which would not have left much meat in the head. The reason the Time-Serts can be so thin is the inner and outer threads are synchronized so the peaks and valleys line up. (See picture below).
Next up is cleaning the carbs and installing the new bits from the K&L carb kits.
Top Pic: Time Sert cutout showing thread alignment.
2nd Pic: Time Sert Kit with drill, counterbore, tap, and installer (this is a thread rolling tap that forms the final threads on the bottom of the instert as it is installed)
3rd Pic: Holes prepped for install
4th Pic: Inserts installed
Why not helicoil ? There was no real need to do a timesert.
Cool.
Buddha.
That does a nice job I must say.
Y
Quote from: The Buddha on January 19, 2018, 01:12:55 PM
Why not helicoil ? There was no real need to do a timesert.
Cool.
Buddha.
I don't realy like helicoils. Once inserted they can be a little tricky to start the threads and I've had experience with them bending at the first coil. I prefer a solid insert. I chose Time Sert because they are thinner than most inserts and require a smaller hole. Once you own the kit the inserts are only a couple dollars each and this thread size is popular on motorcycles.
That being said a helicoil probably would have worked fine since I am changing to studs but since I didn't have a helicoil kit already I chose to pay more and get what I believe are a better product.
Ken
Not that you care, but IMHO, overkill is a great idea here. A solution that results in a reliable repair is a winner. Plus now you have the tools to do this kind of repair again in the future if need be. Total win. :thumb:
Quote from: Kenner on January 20, 2018, 03:40:40 PM
YQuote from: The Buddha on January 19, 2018, 01:12:55 PM
Why not helicoil ? There was no real need to do a timesert.
Cool.
Buddha.
I don't realy like helicoils. Once inserted they can be a little tricky to start the threads and I've had experience with them bending at the first coil. I prefer a solid insert. I chose Time Sert because they are thinner than most inserts and require a smaller hole. Once you own the kit the inserts are only a couple dollars each and this thread size is popular on motorcycles.
That being said a helicoil probably would have worked fine since I am changing to studs but since I didn't have a helicoil kit already I chose to pay more and get what I believe are a better product.
Ken
One reason I love helicoils is that the wire they are made of are very very thin and hard as the dickens. Basically spring steel.
In any case its in place so you're good.
Cool.
Buddha.
Welcome back everybody!
The site has been crashed for a week or more so I haven't been able to post any updates. I have continued to make progress at a slow and steady pace since my last installment. I ordered a bunch of parts from a motorcycle recycler outfit based in Missouri (I am from Utah). I was able to swing a package deal since I bought a bunch of things at once. Namely, a seat, stock airbox, left hand controls, and exhaust (he cut the header and can apart to reduce shipping by $50 then I just welded them back together....I probably should have just paid the $50 though because I only have a Lincoln Tombstone 220V AC stick welder and it was tough to join the pipes together and make it look nice).
I have the header and seat installed. I took the front fairing off to repair a couple of cracks. I also removed the stock petcock since it is leaking. I purchased a crf250x petcock because it is plumbed similarly, but is not vacuum operated. This also allowed me to remove all the vacuum garbage from around the carbs. Trying to make this bike as simple as possible.
I painted the header with some inexpensive grill high heat paint. The paint looks good, but we'll see how durable it is. I first hit the header with a wire wheel in a cordless drill to clean off all the surface rust.
Kenner
Top pic: close up of painted header showing paint used.
Bottom pic: bike as it is today.
If you recall from my earlier post I performed a compression test when the engine was cold and didn't have the carbs installed. The results were:
Left Compression 120 psi Right Compression 120 psi
According to the Clymer manual the compression should be checked after getting the engine to full operating temperature. Now that I have it running I ran it up for about 10 minutes to heat it up and then redid the compression check.
Left Compression 68 psi Right Compression 70 psi
WFT! Why would the compression be so much lower with a hot engine?
Then it dawned on me. Even though I was holding the throttle wide open the slide was not lifting since this is a CV carb and just cranking it over doesn't produce enough vacuum to raise the slide. I reached into the airbox and manually raised the slide while holding the throttle wide open and cranking it over. Then I got
Left Compression hot 128 psi Right Compression hot 129 psi
That's more like it. Interesting to see the difference between hot and cold compression is about 8-9 psi. I didn't have an issue when the engine was cold because the carbs were not installed. Lesson learned.
Ken
Update of tonight's work. I was able to get Yellow Bird's fuel lines replaced and I eliminated the vacuum petcock and instead replaced it with one from a CRF250X. I love how much simpler the new one is. I was able to make it fit quite nicely by sawing a small groove in the original petcock mounting plate. You can't see it in the picture below but on the back side of the petcock there is a small flange that needed a slot to seat in. When seated properly the petcock doesn't twist even though it is only held in with a single nut and bolt. I was able to start the bike up and give my youngest son (4) a ride around the block. It was really fun as the weather here lately has been much more spring-like than winter-like.
Still lots of odds and ends to complete but with the nice weather my garage time has been rather pleasant.
Ken
sweet progress
(https://media.giphy.com/media/gtYaab8vCMWU8/giphy.gif)
Standard fuel line system is a nightmare. looks like it was just tacked together...
Engineer: There I have finished the fuel lines
market exec: BUT you can't reach the tap and the needles and seats are crap.
Engineer: OH, OK here is a new one wit a vacuum shutoff
market exec: What about the reserve.
Engineer: OOps I forgot OK here is a tap you can reach with a vacuum shutoff and TWO lines leading into it . One from the revserve and one from the main. BTW the ends are different sizes now.
market exec: What about a prime when there is no fuel in the bowls and the vacuum isn't letting and fuel through.
Engineer: THERE satsified now.
market exec: But it now weighs more then the bike and needs an fluidics engineer to figure out how to connect it.
Engineer: That's OK put a section in the owners manual saying " if you need to connect the fuel hoses contact you dealer" that always works for a bit extra cash.
How did you block the other tank outlet? I turned down a brass plug and soldered it in one of the outlets. Brasss in getting really hard to find. Of course when I deconstructed the tank tap to solder it, I found the rubber O ring was perished and now I have to find that right sizes fuel resistant O ring.
Most of the way through my fuel pump/shutoff mod.
Quote from: gregjet on February 07, 2018, 01:01:42 PM
How did you block the other tank outlet?
The easy way. I didn't block it off. The manual fuel tap I bought is designed similar to the GS500 one in that it accepts separate inlet lines for On and Res. This tap just allows me to get rid of the vaccuum lines and is only $30 to replace vs $100 for the stock unit. By much simpler I was referring to the petcock itself. I still have a mess of fuel lines hidden under the tank.
In the future I would consider a single tap out the bottom of the tank with only an On and Off, but this was the fast easy solution for now.
The picture above of my petcock was very poorly lit and a little out of focus so I'll try again when I have good daylight.
Ken
Below is a picture of the petcock I installed. It is from a CRF250X. Note the dual inlets and single outlet.
Nice solution kenner.
Run the single line into a quick disconnect connector and you have the best line passive line solution I have seen so far.
I put the pump in to also see if it would help the fuel starvation problem at upper revs ( not that I get to use upper revs around the roads here). Also because it has a fuel shutoff when not powered.
It occurs to me that an electric fuel valve (aka fuel shut off solenoid) like this one (http://www.dan-marc.com/79-afc11112.html) would simplify and solve this problem very well without requiring vacuum.
Hook the electric shut off valve to the reserve tank line and plug the other tank outlet as gregjet did. Other end to the carb inlet. Cap the carb vacuum port forever.
Wire it to the keyed power source (on = open).
This would solve the prime problem.
Only real downside is you might leave the key on and if you have leaking float needles then you could flood the bike just like leaving it on PRI. I guess the other downside from a safety standpoint is that if the fuel line on the carb side were ever cut/disconnected/loose etc. then it would gush fuel as long as the key was on. Or if you lay the bike down it would run fuel out the overflow even if the engine wasn't running. This is no less safe than a manual petcock.
Next time I have to go fool with the carbs or if I have reason to take the tank off.
I like the idea of a solenoid switched with the key. Super simple and nearly foolproof since I almost never leave my key on for fear of running the battery down. Only drawback is loss of reserve which has saved my bacon on multiple occasions.
Ken
The shut off solenoid was my original idea , but I couldn't find one after a lot of searching ,that wasn't the size of a small planet. That, plus ebay has now stuffed it's search, so even if you search for Australian sites, you get US ones, and small items often cost a fraction of the freight cos,t so are economic. I end up buying nothing. Then after reading various posts on the forum I figured a fuel pump may solve a number of problems in one hit. The bonus was having the now spare air solenoid 12v wire and socket sitting in the right place to use.
BTW the size of the one you posted is pretty good but the pipe ID is only an 1/8" (3.2mm) . As there is only tank pressure behind it I may not have sufficient flow?
YellowBird got a little more love as I continued the march forward today. I installed a new left hand switch from an 09 that I purchased with a bunch of other parts for the bike. Turns out the wire connector for the 04 is different than for the 09. I could either cut and splice the wires or remove the pins from the connectors and swap them. I chose to remove and swap them. It worked out pretty good too. The pins looked slightly different so they were not direct replacements, but I was able to drill out the old connector housing and hot glue the pins into place. Fortunately, the wiring colors remained the same. The 04 had 2 connectors, 1 with the 2 wires for the clutch sensor and the other with the blinker and horn wires. I chose to make a jumper for the clutch connector to remove a possible future failure mode with the clutch kill switch.
After getting the wiring sorted out I put the bike together and went for a ride. Boy is this thing gutless compared to my other 04F (the blue one that sometimes shows up in the pictures). I think it is related to the low compression so I began to investigate that. I decided to do the add a bit of oil to the cylinder trick to see if it would raise the compression. Here are my results:
Left (psi) Right (psi)
No Oil 120 120
5 ml Oil 152 152 (teaspoon of oil)
10 ml Oil 180 184 (2 teaspoons of oil)
While the compression did increase, I got to thinking about the amount of oil I was adding in comparison to the size of the combustion chamber. A quick back of the envelope calculation assuming each cylinder is 250cc and has a 9:1 compression ratio. That means the combustion chamber is ~250/9 = 27.8 cc. Adding 5 ml (or 5 cc) reduces the combustion chamber size to 27.5-5= 22.5 which means the compression was increased to ~11:1 ( from 250/22.5) and with 10 ml it raises to 14:1. I assume increasing the compression would increase the psi, the question is would it increase it by the amount of my increase or by less and the oil sealing leaking rings was increasing it more. You notice the increase is directly proportional to the amount of oil added. 5cc increase 30 psi and 10cc increased 60 psi.
While I ponder these findings I plan to check the timing to make sure it isn't just off time a little causing the low compression. I found a post a while back by Addidasguy where he built an engine from components of 4 old engines. It ran, but poorly. He had compression similar to mine (120psi) and he found the timing was out. Once fixed his bike ran great. I'm hoping to find similar. I should have checked to make sure the timing was right on when I checked the valve clearances, but I didn't think to.
Ken
Top Pic
Mismatched connectors.
Next Pic
Removing pins from housings. Pins from old housing came out fine, pins from new housing required a little more persuation.
Next Pic
Connectors together. Note the hot glue on the back and the clutch bypass jumper in the small connector.
Last Pic
Bike as it is today. I purchased a rear cowl off eBay since my bike didn't come with one.
Always trust Adidasguy. Did you (or a previous owner) ever have the timing chain loose or off?
But it could also be a bad vacuum leak or torn diaphragm or something like that causing the slides to stay down, you never get on main jet. I always guess carbs first.
BTW when my bike went under the knife it had about 110 psi one cylinder and 80 the other iirc. After the top end rebuild with 180+ both sides the bike did not have noticeably more power. Now I hadn't really gotten to ride it a lot with low compression because it wouldn't really run when hot but you think I would have noticed the day I picked it up from the shop. And I expected to, but it wasn't different as far as I could tell. Plus all of the other work carb tuning etc that I did since also didn't affect power really, mostly just consistency and idle quality, starting behavior, etc.
FYI.
Quote from: Kenner on February 06, 2018, 11:40:42 AM
If you recall from my earlier post I performed a compression test when the engine was cold and didn't have the carbs installed. The results were:
Left Compression 120 psi Right Compression 120 psi
According to the Clymer manual the compression should be checked after getting the engine to full operating temperature. Now that I have it running I ran it up for about 10 minutes to heat it up and then redid the compression check.
Left Compression 68 psi Right Compression 70 psi
WFT! Why would the compression be so much lower with a hot engine?
Then it dawned on me. Even though I was holding the throttle wide open the slide was not lifting since this is a CV carb and just cranking it over doesn't produce enough vacuum to raise the slide. I reached into the airbox and manually raised the slide while holding the throttle wide open and cranking it over. Then I got
Left Compression hot 128 psi Right Compression hot 129 psi
That's more like it. Interesting to see the difference between hot and cold compression is about 8-9 psi. I didn't have an issue when the engine was cold because the carbs were not installed. Lesson learned.
Ken
128 psi is good, it will run with near 100 psi cold and 110 hot - I know that for a fact, I ran one to there and it still ran well. Down on power compared to a higher compression motor but ran fine enough.
Cool.
Buddha.
Quote from: mr72 on February 10, 2018, 07:08:50 AM
Always trust Adidasguy. Did you (or a previous owner) ever have the timing chain loose or off?
I've never had the head off myself, but I did notice some pry marks (can be seen in the earlier photos showing the exhaust studs) making me think the head has been off before. The ODO shows about 19,600 miles but I have no idea whether that is accurate. The guy I bought it from owned it for about 5 years but only put 350 miles on it (according to the title). I am inclined to believe that is true too because it had last been registered in 2014 so it sat for about 4 years before I bought it. The kid was pretty young and lived at home with his dad. It looks like it was a project bike that never got finished (unfortunately his idea of project was to cut and remove things like the muffler and stock airbox just looking for more noise I guess).
I did check the valve clearances again since I've had it running (albeit poorly) for a bit and they were all within spec. I verified the timing was correct as well and as far as I can tell it appears OK. The 1 and 3 marks were correctly pointing at the chain when the cam grooves were pointing at each other and they were 18 pins apart. They did seem off a tad but way less than 1 tooth on the sprocket which might indicate a stretched chain.
I already redid the carbs with all new O-rings and eliminated many of the vacuum lines so I hope I eliminated any potential vacuum leaks. I inspected the diaphragms when I had the carbs apart and did not see any tears or pinholes. I ordered some new O-rings for the intake boots because I did not replace those. I do have the nice running blue bike and I am tempted to swap carbs and see if it runs better with those to see if the carbs are the problem. I will do that when my new O-rings come in and I pull the carbs to install them.
Ken
I did a bit more work on Yellow Bird today. I pulled the airbox off and started her up. I was able to see that the slides would move up and down when I revved the engine hopefully indicating that my diaphragms are OK. I took my son on a little ride just to get the bike warmed up enough that it would idle without the choke.
Once it had a stable idle I sprayed a little starting fluid around the carbs listening for any engine rev increases. I noticed a slight increase when fluid was sprayed around the right intake boot. I have new O-rings on order so I will replace those when they come in. I also bought a lunchbox filter and larger jets from a seller in the "for sale" section so I plan to put those in to richen it up to match the increased airflow.
I am still dealing with a serious lack of power. The vacuum leak that I found seemed quite small because when I sprayed a bit of fluid there the rpm increase was very slight, barely registering on the tachometer. Would such a small change really be the cause of my missing power?
Ken
Another small trick to share is when working on the engine, if the fuel lines are long enough you can place a small sawhorse next to the bike and strap the fuel tank to it while doing some maintenance eliminating the need to unhook the fuel lines. I was able to check the timing, valve clearances, and compression with the tank situated like in the picture below.
Handy diagnosis tool is a laser thermometer. Mark a point on the exhaust where the temps should be the same and take readings there. Any differences will show up really well. And you can do it ant any revs ( and if you have a dyno any load).
My new carb intake boot O-rings arrived today. I removed the old, flat, crusty ones and replaced them with the new flexible rings. Unfortunately, it did not improve the running of the bike. It still has almost no power when under load. It also does not idle as it should. When the choke is engaged it does not rev up to 3-4k rpms like my other bike. I plan to swap the known good working carbs from the other bike onto this one to see if they are the problem. I hope it is, but in the back of my mind I kind of hope it is not since I already went through the carbs cleaning them and replacing the O-rings. If it is the carbs it still means I have much to learn about performing a carb cleaning/overhaul (edit: both sets of carbs work fine so it looks like my cleaning and overhaul procedure is sound...nothing like having others critique your work to make you doubt yourself).
Wish me luck!
Ken
You are ruling out the potential issues, that's a good thing. You have to make educated guesses. Swapping for known working carbs will certainly be a helpful way to isolate whether the problem is with the carbs or not.
To be low on power requires either bad compression or inadequate fuel (and air ... but in a CV carb they are necessarily related). Swapping the carbs will tell you whether the compression is at fault. And as a bonus, if it turns out it is the carbs, then you already have them off the bike!
You just have to be logical about it. If it's the carbs, then it means either:
- adequate fuel is not getting added when the throttle is opened
- the slide is not coming up and the needles are still blocking the main jet -- you verified the slides move up when you open the throttle, so this is not it
- fuel is not getting to the main jet when the slides come up and the needles are out -- this is maybe low floats, sticking float needle valve, clogged float valve, clogged passageway in the main jet fuel supply
- air is being added in bulk past the point of the jets so it is not mixed with fuel
- it could be a bulk air leak, which you began to rule out with the big o-ring swap, or some other major air leak somewhere else like a completely missing o-ring or vacuum cap gone
We're not talking about tuning but gross diagnosis of a big failure. It sounds like it's just not ever running on the main jet so I suspect fuel supply especially if the slides are clearly moving all the way up when you open the throttle. But it could be that vacuum is sufficient to pull the slides up but also air is being sucked in somewhere past the jets keeping it very lean when the slides are up.
Is there any chance the wrong jet is installed? Maybe the mid and main jets are swapped? Or the wrong main jet is installed? Should be pretty obvious, right? Don't the Mk2 carbs have a pretty big main jet, over 1mm? You can eyeball that.
I can't count the number of times I had my carbs apart trying to sort them out before finally discovering it was bent valves all along. That includes two sets of carbs! And several times I tore them down and found mistakes I had made putting them together the previous time.
When you cleaned the carbs if you check the emulsion holes in the sides of the main jet holder/emulsion tube. They are extremely tiny and block with almost anything. If they are blocked they will stop the needle and mainjet working properly. They are also very hard to clean properly. They are also the first thing to suffer from alcohol fuel because they are so tiny and in a air/fuel mix environment. Unlikely to the the alky problem but I have seen it, especially on bikes that have sat for a long time with fuel in the bowel. Usually there is a lot white corrosion inside the bowls when you open them. If there was lots when you first opened the carbs they MAY be unsavable.
Mine was a VERY stuffed bike when I bought it and it had been sitting for ages. I ended up cleaning the carbs 3 times before I managed to get them running properly,then they were fine. Replaced the needle and seats, because it's a Suzuki, and i could NOT clean one of the pilots without stuffing it. Nothing would get the grunge out of one of the jets. Clogged solid. Bought new pilots, and both mains, which fixed them, but the galleries were full of junk.
Agreed. I used a guitar string to clean mine. And cleaning a 0.4mm jet is a fools errand when they are 5 dollars each.
My pilot jet wouldn't even unclog with a guitar string. It was seriously grunged...
Yeah, no kidding. I would always just replace the pilot jet. It's too small to try and clean anyway and the fact is just a tiny amount of gunk would cause a serious impediment. Those Mk2 carbs especially, with a 0.2mm pilot jet... that's smaller than a 0.010" guitar string! Think about that. An ordinary piece of copy paper is about 0.08mm thick... over 1/3 of the entire size of the pilot jet. To "clean" a pilot jet like that would require using a 0.2mm drill bit, which nobody has because that's unbelievably tiny.
But you can clean the fuel orifice under the pilot jet with a guitar string... it doesn't have to be a precise diameter. But it does have to be not-clogged. I used a piece of a 0.013" and a 0.018" guitar string to clean mine, dunno about the Mk2, probably need smaller, and smaller than 0.013" is not rigid enough to use for cleaning.
Better still is to strip the carb down to only aluminum parts and then put it in an ultrasonic cleaner.
I use 8-40 or 42 srings on my Tele ( heavier on the Strat 10-46). That's .2mm and 10's are .22mm.
The problem with using guitar strings is they can scratch the inside of the jet oriface. This can and does cause flow disturbance through the jet. This is especially true if the string has been cut with side cutters. As the end is wider than the original string and much sharper.
wow, those are pretty tiny strings. Smallest I have are 0.010s. Good point about scratching the brass jet. All the more reason to just replace.
mr72 and Gregjet,
Thanks for the replies and suggestions. I haven't had much time to work on the Yellow Bird lately, but I have appreciated your insights.
This weekend was spent at my friend's cabin which is at 7000' near Bear Lake, UT. We got 24 inches of snow on Saturday night while we were there. It was amazing! I have 3 little kids ( ages 4, 8, & 10 .... there were 12 kids total at the cabin) and we had so much fun playing in the snow, sledding, and building snow forts. The snow is really good for us here in UT too because this year has been super dry and unseasonably warm.
Now that a cold front has moved in I am reluctant to do much work in my unheated garage. Call me a wuss, but I prefer to feel my fingers :laugh:. I have a couple of space heaters that I'll probably pull out in a day or two. For now I have to finish unpacking from our weekend trip.
Ken
Kenner, It has been over 45deg C (113F) in my shed. Maybe I should send you some of the extra heat for your workshop. Sometimes too hot to breath in there.
Quick update. I haven't made headway with the Yellow's poorly running engine, but I did do some work earlier that I failed to mention. I added some bar risers and some new handlebars. The handlebars on the bike were bent and rebent multiple times so they looked awful when I got it. I had a spare set from a DRZ400 lying around so I put them on. I also purchased some fairly cheap eBay risers. I much prefer the more upright seating position now, but the bars are a bit wider than the stock ones which makes turning feel a little odd at full chicken (edit. I originally put the other word for rooster here and it got updated to chicken (does the forum have some words it automatically changes?)...funny!). I am deciding if I want to cut them a 1/2 inch narrower on either side. I realize I should have taken the picture further back to show the whole bars, but I was more focused on the risers at the time.
The risers I ordered were: https://www.ebay.com/itm/Pair-1-1-8-7-8-Universal-Bar-Clamp-Riser-Taper-Handlebar-fit-Dirt-Bike-22-28mm/332422420831?ssPageName=STRK%3AMEBIDX%3AIT&var=541452464351&_trksid=p2060353.m2749.l2649
They were only $15 and I am pleased with the quality. The only drawback is the spacers that they use which go inside so it can mount either 7/8 inch or 1 1/8 inch bars. They were a little squirrelly to install. Once tightened down they feel fine.
Ken
I had a chance to do the carb swap today. Good news. Its is not the carbs. Bad news, it is not the carbs.
I put the carb bank from the Blue 04F on Yellow Bird and it ran just about the same. It was hard to start and it had almost no power under load. Just to double check Yellow's carbs, I put them on the Blue machine and it ran like a top. Both sets of carbs were just overhauled by me and they both work fine.
Now on to what could be causing Yellow's lack of power. The trifecta of an internal combustion engine is fuel, fire, and compression.
I know it is getting fuel (at least I know the carb bank is good).
The compression is low, but others have ran their bikes with less.
That just leaves fire. I already installed new spark plugs. I plan to check to coil resistance and also check the timing with a timing gun. I have already mechanically verified the timing by pulling the head and checking the timing marks on the cams with the mark on the ignition.
What do you think?
What should I troubleshoot next?
Ken
I'd be doing the same you are. Eagerly waiting for your findings!
Quote from: Kenner on February 21, 2018, 07:01:34 PM
The trifecta of an internal combustion engine is fuel, fire, and compression.
I know it is getting fuel (at least I know the carb bank is good).
The compression is low, but others have ran their bikes with less.
That just leaves fire. I already installed new spark plugs. I plan to check to coil resistance and also check the timing with a timing gun. I have already mechanically verified the timing by pulling the head and checking the timing marks on the cams with the mark on the ignition.
What do you think?
I think you're barking up the wrong tree with ignition. But hopefully I'm wrong. At least it's easy enough to check the same way you did with the carbs: swap the coils and CDI from the working bike over to the bad one.
Now, you could have the ignition timing way wrong, you could have the valve timing somewhat wrong. So I suppose it's worthwhile to double-check that, maybe even do a comparison with the working bike just to be sure your procedure is good.
But in the end, IME anyway, with electronic ignition, they fail in a binary fashion: either it fires or not. You don't get low power due to poor ignition. This is not a 1950s VW with points. So you might be running on one cylinder (bad coil, wiring) , or you might be running on one cylinder only when it gets hot (bad hall sensor in the signal generator, bad coil). Maybe check by pulling one plug wire at a time when it's acting up and see if pulling one has no effect (that's the bad side) or pulling one kills the engine entirely (only good side). Likely not the CDI/ignitor because it would just die. Likely not the signal gen, again usually they get hot and fail completely, bike dies when hot. Likely not bad wiring, that would not cause it to run bad only at high revs/load.
It could be resistance in the wiring in series with the coil causing the coil charge/discharge rate to slow so that it can't keep up at high revs. Unlikely though. You can ohm that out easily enough and rule it out. So if you're really convinced it's maybe ignition I'd start with chasing the wiring with an ohmmeter and make sure it's all good, then swap coils bike to bike or do the plug-pull check (or both), and once you rule out ignition then you know what the problem is.
My money's on compression. I hope I lose :)
Quote from: mr72 on February 22, 2018, 08:26:40 AM
Maybe check by pulling one plug wire at a time when it's acting up and see if pulling one has no effect (that's the bad side) or pulling one kills the engine entirely (only good side).
I have a question regarding pulling a plug wire while the engine in running. In the Clymer Manual it warns that the plug wires/coils need to be grounded while performing a compression test so they recommend inserting the spark plug and grounding it to the head while performing the compression test. If I remember correctly this is to avoid a potential overload of the coil.
I have read in a number of places that a good way to test for a dead cylinder (and even a quick way to check carb synchronization) is to pull the plug wire while the engine is running and listen for any changes. Pulling the wire is essentially opening it up, doing exactly what the Clymer manual is warning against. My question then is the Clymer manual recommendation overly conservative and pulling a spark plug wire while running is not risky to the ignition system?
Ken
I've never heard of that risk, but I've never read a Clymer manual either.
I have done the "plug pull" many, many times on a running engine to diagnose issues and never had it make the coil go bad.
The coil won't discharge if it's not provided a sufficient path to ground. I suppose there is a chance that it will become charged sufficiently to break down the lacquer insulation on the wiring in the coil. It's no different though from a bad coil wire.
Prime use for a laser thermometer. Measure the temp in the same place on the exhaust header near the head. It will tell you straight away.
They are also really good for telling you if your beer or champagne is cold enough.
Quote from: gregjet on February 22, 2018, 12:56:55 PM
Prime use for a laser thermometer.
Grejet,
I read your other post about a laser thermometer and I really wished I had one. I may have to get myself an early birthday present (my B-day is not till April).
Ken
They aren't that dear. And you have to ask yourself, how much is the correct temp beverage worth?
Even in Aus they are reasonable
http://www.supercheapauto.com.au/Product/SCA-Thermometer-Infrared/321439
If yellow bird's carbs run good on blue bird and blue bird's carbs run like crap on yellow bird, I'd likely suspect yellow bird's fuel supply/flow is messed up.
Yes get laser thermometer and other cool sheite ... cos those are just cool as duck ... but your problem could be something far far less cool, like the retarded A$$ petcock and the retarded A$$ other petcock etc ...
Cool.
Buddha.
Quote from: The Buddha on February 23, 2018, 09:01:54 AM
I'd likely suspect yellow bird's fuel supply/flow is messed up...your problem could be something far far less cool, like the retarded A$$ petcock and the retarded A$$ other petcock etc ...
Thanks for the idea, but I doubt it is the fuel delivery because I have replaced the vacuum petcock on Yellow with a manual one from a CRF250X (in your words eliminating one retarded A$$ petcock ;)). Blue still has the vacuum operated petcock and its the one that runs fine.
I could always try a test by turning the fuel on with the lines not connected to the carb and catch the fuel in a bowl seeing how fast it is flowing.
My issue now is that the bike will idle, but if I try to load it (like simply taking off from a stop) it bogs down and nearly dies. Just to get the bike moving I have to rev it to 4-5K and slip the clutch a lot. Once moving it will accelerate very slow, but I have yet to get it to go over about 40 mph.
If It sits idling and I twist the throttle it will rev up, but not as quickly or cleanly as Blue will do.
Maybe I should post a video?
Ken
yeah that could definitely be fuel flow. Maybe hook up a fuel container directly (no petcock) and see if it changes things.
I found the culprit. Turns out the problem was "Fire". One of the Yellow's plugs at the back of one of the coils was disconnected. Not sure if it is the ground or the secondary coil wire but once I plugged it in it ran pretty good. Since it snowed about 3 inches today I was not able to take it out on the highway, but I did do a loop up and down the street a couple of times and if feels like it is running pretty good.
It did backfire a couple of times when it was cold. I didn't notice it backfiring once I warmed it up, but I didn't ride it much either. It has the lunchbox filter on it now and the jetting is set to 20/60/145.
I bought the filter and jets off one of our forum members.
Do others running the lunchbox experience backfiring?
Ken
Circled wire in image below was disconnected.
Pretty sure , if the 04 is the same as an 05 that there is no earth wire as such. One wire goes to 12V and the other to the ECU ( although the ECU wire is a kind of earth wire). Just found that out when I was wiring in the coil on plugs.
Thanks for the info Gregjet.
I started up Yellow again today and took her for a ride up and down the street (not very far since it is about 20°F outside). Yellow now runs better than Blue. Its great!
I posted a video of Yellow running on Youtube here: https://www.youtube.com/watch?v=RsuSAJ3Ht-A
You also get a sneak peak of Blue in the video.
Ken
sweet! ! ! (http://www.motohouston.com/forums/images/smilies/headbang.gif)
I got both Blue and Yellow completely put back together today! I decided it was time for a photoshoot. Enjoy!
Ken
Now what to do with 2 running bikes........?
Good looking bikes--clean and not scabbed. I have always liked the blue ones best, but the only one I found to buy at the right price is black and a little scraped up. I have not seen a yellow one except in pictures. Again, you have good clean bikes.
Hi all,
I have been riding both bikes for the last month and they are sure fun. The blue one is definitely all round the better bike. It is smoother, feels tighter, and looks better.
I have been contemplating a new project for the Yellow Bird. I acquired a frame from a 2005 KX250F. I have considered putting the front suspension from the KX on the GS making it a little more of an adventure bike.
I did similar to my wife's TTR230. I put the front suspension from a DRZ400 on it that I got from my neighbor after he blew up the engine.
I think adding a stiffer and longer travel front end will make it a blast down simple dirt roads. If I am happy with the new front suspension I'll do something to increase the rear travel.
It'll take a while before I get started since I prefer to ride in the fair weather and wrench during the winter, but it's always nice to anticipate the next project.
Ken
Kenner,
If you decide to increase the rear travel let me know how much you are aiming at. I have the Tony Foale suspension software and , of course have the gs500 rear suspension already measured and modelled so I can do so simple design testing.
Even though the gs is heavier longer travel usually means lower rate suspension ( though I can model that as well) and get a ball park spring rate for any travel.
Interesting you may be able to swap the shock and swingarm links to get travel increase, though I haven't modelled it yet.
Quote from: Kenner on April 08, 2018, 05:43:07 PM
I have been contemplating a new project for the Yellow Bird. I acquired a frame from a 2005 KX250F. I have considered putting the front suspension from the KX on the GS making it a little more of an adventure bike....
I think adding a stiffer and longer travel front end will make it a blast down simple dirt roads. If I am happy with the new front suspension I'll do something to increase the rear travel.
My dad's been looking for a dirt-road bike and he's looked at the usual KLR650s and the like, I tried to convince him maybe he should try a modified GS "scrambler" style simply because I know all about how to work on it. Biggest killer is weight, although it's just about the same as a KLR650.
I bet you'll have to swap the springs in the KX fork. You'll definitely have to increase the ride height in the rear and maybe the travel. A Katana 600 rear shock may get the job done for you; it's a stiffer spring and with any preload at all will raise the rear over an inch while riding. But my guess is you will need a couple of inches, which will mean a different (custom or adjustable) dog bone link.
Sounds like a big project. Also sounds like you'd be better off starting with a different platform to make a dirt-road bike.
Maybe just to ride on gravel or dirt roads you'd just change the tires to 50/50 and handlebar to a tall MX bar or KX bends with 1.5" risers. Swap springs front and rear to get an inch less sag. Put on a round headlight with a rock guard on it and take off all of the plastics. Call it a scrambler.
I guess there's a progression from dirt bikes to road bikes and you can probably modify a GS500 reasonably easily to get it near the 75% mark, while a KLR650 is more like the 40% mark. Your fork swap will get a GS close to the 50% mark if you do the same at the rear, maybe even swap the swingarm and rear wheel. But then that's a rather different bike altogether, and if it were me I'd start with a different bike if that's your intent. I think there are a lot of little things that are not easily altered (foot peg position, length of the tank, low end torque, etc.) that may seriously limit a GS500's usage truly "off road" where there is any obstacle bigger than your two fists to go over. But where there's a will there's a way :) You've shown you can fix dang near anything if you want to.
I haven't had much time to work on the motorcycle lately because I have been overseas for a while (in southwest Asia). Since I couldn't work on the bike, I thought I would read a book that I have heard a lot about which I hoped would improve my maintenance skills. The title is "Zen and the Art of Motorcycle Maintenance: An Inquiry into Values", by Robert M. Pirsig. I came across multiple posts in a variety of forums praising this book. Unfortunately, it was not what I was expecting at all. Honestly, I can say I didn't like it much and it was a waste of time to read. A more accurate title would be "Zen, Philosophy, and two pages about motorcycle maintenance", since that is about all the copy that was dedicated to the subject of maintaining motorcycles.
I am an engineer which means I tend to be more analytical and logical. Reading this book tested both my analytic and logical patience. I was hoping to improve my motorcycle maintenance skills, but instead I was presented with a book that bounced back and forth in timeline, was difficult to understand, and presented odd philosophies. If debating and philosophy are your thing, you'll probably like this book; but since I don't really enjoy either of those activities this book was somewhat painful to read. I realized I'd been duped when I was about a quarter of the way through the book, but I continued and finished it just in case there were any hidden gems.
I appologize for the off topic comment, but since I can't work on my bikes now all I can do is continue to think about them and make plans for what I want to do when I get home. Then posts about actual motorcycle maintenance will continue.
Ken
I'm with you on that one!
I thought that book was required reading for any "real" thoughtful biker, but man was that a boring read about hippies on Harleys.
" Zen and the art..." I read it many decades ago, but I did come to it knowing it wasn't about fixing motorcycles, but fixing people. I possibly saved my life. Not by some mystical whimsy, but but the notion of dumping the crap when you are getting overwhelmed and concentrating on the now and what is in front of you.
Does relate to fixing motorcycles in a sort of "Sun Zu's Art of War" relates to conflict way, if you think about it.
Now back to the yellow...
Hello Everybody!
I'm back from my overseas "vacation". I decided to pull the bikes out of storage and get them running again. Old Blue didn't take much to get back into working order, it just smoked a little on the first couple of rides due to the oil I put down the cylinders when I stored them. Yellow Bird on the other hand is giving me fits again! Mainly carburetor issues. When I turn the fuel on one of the carbs leaks fuel. I took them apart and looked for any gunk, but they were still quite clean. I believe it is the needle and/or seat that is leaking. I ordered a rebuild kit.
I just overhauled this carb last year when I did all 4 of the carbs on the 2 bikes using K&L kits from eBay. An OEM needle and seat is north of $50 so I am going to try another aftermarket kit. So there's a few data points for you: 3 of the 4 aftermarket kits are holding up well after a year of storage. I found an eBay seller that has kits even cheaper than the K&L, I may regret going with them but for the sake of experiment I'll try the lowest cost option and see if it holds up.
I can still ride the bike because the fuel leak is only noticable when stopped. It burns fuel fast enough when going that it does not drip. I want to put a few more miles on the bike to see if any more gremlens show their faces.
Wish me luck.
Ken