On Sunday evening I went for a 45 mile spin down I-90 to Yakima. Lots of big hills but the bike handled like a champ for the most part keeping pace at 70 the entire way.
Hung around for a bit, gas'ed up and headed back, again the bike was great.
So I parked it Sunday evening, and then today I go out for a ride, after cruising around for a little while I decide to hop on I-90 and get off at a lake just a few miles down.
To my surprise, when I cranked it open I got the infamous BRRRRRwaahhhhhhhhh as it started to accelerate then bogged out.
What could have happened? It's been doing great for the most part and was parked still doing fine. It should have been all warmed up from the town driving and there's plenty of gas in the tank.
Last time this happened it was only running on one cylinder, but would backfire on decel. And that's not happening this time. I did check the plugs, and all the air/fuel lines to make sure nothing got pinched while it was...sitting there. :confused:
When you crank it open it starts out fine then just dies off, and starts lurching with odd surges of power, it's really bizzare. But when you let off it just casually comes back down.
Although now reving it up while it's sitting in neutral, if you take it to like 8-9k it makes a bounce at 6k on the way down, then drops to idle.
The only thing I could think of was bad gas from Yakima? Maybe I was out of it and put the wrong thing in? :cookoo:
Or something got really hot from the long trip and...broke as it cooled down? (grasping at straws)
Just trying to think of what kind of issue would arise after the bike had been parked :dunno_black:
Any insight or solutions to a similar situation would be fantastic.
-Wright
The things I would check and/or replace.
Replace carb vent line.Bees can build nest in the line and partially to completely block it.
Check and/or replace the frame petcock.I have a write up where I replaced mine with one from an 04-07 Honda CRF250X petcock.A lot cheaper that stock by about $60. http://gstwins.com/gsboard/index.php?topic=56352.0
Check and clean the fuel cap vent. http://gstwins.com/gsboard/index.php?topic=41061.0
Thanks for the advice. Will have to look at a diagram to figure out which lines those are, though I checked all of the larger ones for kicks. And that seems crazy that they could have gotten clogged in the 24 hrs it sat there, haven't even seen bees around here yet. *shrug*
Also, I did get a new chain about a week before I went on that ride...not sure if that could be anything. Seems a bit small for the GS but obviously it was fine for that one ride.
While I had the tank off I checked the head cap, and the two front screws were totally loose, which explains the oil leak, took it off, cleaned around the edges, put the gasket back in and tightened it snuggly back down.
While I'm not opposed to replacing the petcock, as it doesn't look too difficult, I'd rather not spend money until I know if that's it, little tight right now.
Also, on the carbs, straight across from the air filters are two white caps, and each cap has two little hard plastic places where hoses go...but there is nothing on them, any clues as to what's going on there? Extra breathing?
EDIT: Found a pic online of what I'm talking about (http://lh5.ggpht.com/_LiiPGd63-PY/TXuyqxQ25qI/AAAAAAAAADk/98yot14AWmQ/2011-03-12_12-39-10_323.jpg) None (Of the 4) have caps on them...
Also made a video of the rev halt on the way down in case anyone's curious. (http://www.youtube.com/watch?v=OcrwdX4th9o)
After tighting the head cap on I took it for a spin to see how the leak was (seems okay now), but while I was out I paid a little more attention to the noise. When you crank it up to go, and it bogs/lurches, it's doesn't sound like it's smoothly lurching. Sounds like, rapid fire, basically if the engine noise was equivalent to a machine gun blast, or gravel in a can (but not a metallic sound of course, just the engine noise). And only at WOT.
Thanks!
-Wright
Also, looked at a hose routing diagram and noticed I have the reserve and main gas hoses flipped, besides being a pain when I run out of gas, should they be switched?
So I was reading through old topics about surging and was out checking battery grounds, couldn't actually figure it is lol. :dunno_black:
Anyway, fired to bike up again just to see. And noticed something that could hopefully be diagnosed. From an idle, opening and holding the throttle all the way, the bike would rev up and stop Exactly at 8k RPM for about a second before then continuing to try and go higher. Just holding it open, zips up and stops at 8k rpms for a bit, then finishes slowly climbing some more. Was definitely not doing that on Sunday...
-Wright
Quote from: Wrightboy on July 13, 2011, 06:34:31 PM
While I'm not opposed to replacing the petcock, as it doesn't look too difficult, I'd rather not spend money until I know if that's it
A good move :thumb:
Nothing stopping you carefully taking it apart and looking for any damage, particularly to the diaphragm. Look for hairline cracks in the casing and also check the vacuum line that runs to the carb, make sure its tight on the stubs and shows no signs of collapsing when it sees vacuum.
My own petcock has lasted almost 17 years to date without issue and of the 30-40 GS5s I have bought and sold I have never seen a failed one. They are not 100% reliable but I don't believe they are as unreliable as they are made out to be. I wouldn't automatically assume this is where your fault lies until all the other possibilities have been ruled out.
sounds like you picked up water on your last fillup ,,put a cup of methalated spirits in tank .give it a shake meths will absorb water and mix with petrol . ido this regulary about every third tank because of crappy petrol here .good luck
Quote from: twinrat on July 14, 2011, 01:52:21 AM
sounds like you picked up water on your last fillup ,,put a cup of methalated spirits in tank .give it a shake meths will absorb water and mix with petrol . ido this regulary about every third tank because of crappy petrol here .good luck
Suppose that could be it, guess it couldn't hurt to just dump some in there.
One thing I was wondering, is there a time in the throttle where like the jets switch or something? Don't really understand carbs that well, but since the bottom end of the bike seems to be perfect and it's only the back 1/3rd of the throttle it makes me wonder if there's like a trigger in there that's switching to like the main jet and it's clogged. (Terminology is probably way off, and I applogize).
Could also explain why it pauses at 8k, if that's when it makes the switch?
- Wright
Those plastic vacuum barbs in the pic link you posted, need to be capped.You could just run a vacuum line from one to the other.
Quote from: ben2go on July 14, 2011, 10:32:10 AM
Those plastic vacuum barbs in the pic link you posted, need to be capped.You could just run a vacuum line from one to the other.
Hmm, guess I could look into that, would that actually be causing an issue? Think it's been that way since I got it. It's a 1990, but I think buddha said the carbs were post 2000 or something :dunno_black:
Also, pulled the carbs for fear it was a clogged jet or something. Noticed the little rubber boots that it attaches too are a little...worse for wear? Should these be replaced or do the insides seem okay?
RightBoot:(http://i.imgur.com/Y7uSL.jpg)
LeftBoot:(http://i.imgur.com/HnbSD.jpg)
Also, what the heck is this supposed to be plugged into lol?
(http://i.imgur.com/vKM1D.jpg)
You guys are the best,
Wright
So jumped into the carbs, not quite sure what's bad and what's not but here's what I've got so far.
Not sure what this stuff is, it was all gooey before I let it dry.
(http://i.imgur.com/MiaHP.jpg)
You can see here the diaphragm was pinched when the cap was put on by the PO, is this cause for replacement or are they pretty tough?
(http://i.imgur.com/sCX9E.jpg)
So I was trying to follow This (http://gstwin.com/carb_work.htm)walk through for carbs, but unfortunately I think mine are different.
(http://i.imgur.com/awQcB.jpg)
What should I be focusing on cleaning with these?
Also, I unscrewed each of the jet's to have a peek inside, inside the right main I found a flake of POR 15 :icon_eek: hoping it's from the old tank and not the new (old) one I just sealed. And I'm not sure if it was enough to actually be causing any issues, as I said before I don't know how much is too much.
-Wright
If the diaphragm isn't torn or have a hole in it,I'd run it.The crap in the carb bowl appears to be fuel tank sealant.You need to disassemble the carbs like in the link you posted.Make sure to pull the emulsion tubes and clean all 8 ports along the sides.Also be sure to clean the holes in the float hangers.I use a sewing needle to clean the holes in it.All passage ways should be cleaned out with carb cleaner or brake cleaner and blown out with compressed air.Things may look different in your carbs,but they work the same with the exception of a mid main jet.
How to remove a stuck slide guide and emulsion tube. http://gstwins.com/gsboard/index.php?topic=24036.0
Quote from: ben2go on July 15, 2011, 03:25:06 AM
How to remove a stuck slide guide and emulsion tube. http://gstwins.com/gsboard/index.php?topic=24036.0
Was curious about this...
From that link and the diagram, this looks to be the slide guide, yes?
(http://i.imgur.com/mgE8I.jpg)(http://i.imgur.com/oDk8C.jpg)
But I've been looking it over before trying to remove it and I don't see how it can come out.
Also, in everyone else's that have the emulsion tube in that thing, but if I'm correct and this is mine, it just screws in o.O (the long one in the picture obviously, could be totally off again here though)
(http://i.imgur.com/hkEC7.jpg)
And the only thing that was in the "guide" was this thing, which fell out when I took out the big one.
(http://i.imgur.com/OqwpH.jpg)
Also, I have this bucket of carb cleaner
(http://i.imgur.com/JZi5M.jpg)
Kinda just want to put the entire carb in there, but i'm not sure what's safe and what it'll ruin. I noticed this electrical thing on the side, wasn't plugged in on the bike and I have no idea what it is. But the carb stuff says plastic is bad =/
So I took it off (hopefully didn't screw anything up), but I can't tell if what it was covering will be safe inside the carb cleaner bucket.
(http://i.imgur.com/IfQdA.jpg)
And all the barbs, will they need to be removed as well before I can dunk the thing?
Thanks,
-Wright
Your bike is 1990 right?
Those carbs are not from a 90'.
I have 2006 carbs on my 2001... and i haven't got it to run decent yet (but then again it wasn't running perfect with the 2001 carbs either [i really need my carbs back]).
That is emissions stuff used on the newer gs500's (the electrical doohickey).
I don't think any one knows what all the emissions stuff really is for (there is a 'filter', a vacuum canister, that elicrical doohicky [Throttle Position Sensor or TPS] (I don't think it does anything even on the newer bikes), and the 2 vacuum port thing-ama-bobbers on top of the carbs, and an electrical switch or solenoid on the vacuum lines.) But mayhaps someone does know.
Good luck.
Oh... and on mine, the 2001 choke cable does not extend far enough to fully release the choke on the 2006 carb... so i've been attempting to use the bike without the choke cable connected (fun stuff) [i need my carbs back].
Just something you might want to check.
(if the choke is stuck open i imagine that would cause lean issues... like a vacuum leak mayhaps...) (on a car i'd be sure what it would cause, but on a motorsickle, i'm not sure... i don't even think it is really a choke... but more of an enrichment circuit... but i don't know).
Those carbs are 04+.Removing the throttle position sensor is fine for cleaning.Don't worry about the slide guides since they are aluminum and you have the emulsion tubes out for cleaning.I have yet to get my hands on a cheap set of 04+ carbs to tinker with.When I do,I will do a write like my other one showing what parts are what.Please let us know how that gunk brand cleaner works.I got some of the new Berryman's Chem Dip and it was crap.
Quote from: ben2go on July 16, 2011, 10:06:23 AM
Those carbs are 04+.Removing the throttle position sensor is fine for cleaning.Don't worry about the slide guides since they are aluminum and you have the emulsion tubes out for cleaning.I have yet to get my hands on a cheap set of 04+ carbs to tinker with.When I do,I will do a write like my other one showing what parts are what.Please let us know how that gunk brand cleaner works.I got some of the new Berryman's Chem Dip and it was crap.
I saw that stuff there, but I've always used gunk degreaser for my car engine and such so I went with them :dunno_black: we'll see though.
Before I dunk the things I was curious about this little guy
(http://i.imgur.com/jT02d.jpg)
It seems like there is a little o-ring in there, and the degreaser bucket says not to let gaskets/rubber/plastic inside it...but I'm not sure if I took that out I'd be able to get it back in right (if I don't lose it).
Also, I'm trying to buy a jet kit from Buddha while I have them out like this, you can see from the pics I still have my mixture screws capped, am I going to have to look into getting those freed in order to use the larger jets? (nothing fancy, just reducing the stock lean).
And this morning I was feeling extra motivated, so I went out and checked all the
valve shims :icon_eek:. The thinnest feeler I had was 0.038mm and it didn't fit behind any of them except the left exhaust, and it was still super tight squeezing it in. Is there a good place to buy shims? They seem crazy expensive on bike bandit. Not sure if there's anyone I could trade my shims for...cause really they seem way to tight. Especially the right intake. Did it how Kerry showed in his video with the plugs out in 6th gear, and every time that one valve would go down it took a fair amount of force to break it free, can't be good for it lol.
Sorry for all these questions, really should have split it up a bit better, or just waited until I had money for a mechanic :icon_razz:
Thanks,
Wright
Remove all rubber and plastic.You should be able to get the O ring back in there.I use a paper clip with the end straightened out and a small L shape bent on the end to pull them out.The valve shims are 29.5.I get mine here http://crc2onlinecatalog.com/valve_shims.htm
Yes Kerry's vid has the plugs out and 6th gear.
Paper clip...paper clip...don't actually think I have any right now. Will have to pick some up next time I'm out.
And is there any difference between your link and this guy? http://www.z1enterprises.com/Valve-shim--295mm-diameter--255mm-160.aspx (http://www.z1enterprises.com/Valve-shim--295mm-diameter--255mm-160.aspx)
Cheaper, and they offer me 2 day shipping, also thinking about getting the tool from there.
You can see the post I made in the for sale section here, (http://gstwins.com/gsboard/index.php?topic=57068.0) was looking for a quick trade, but I might just delete that and go with the Z1 enterprise completely.
But while I have you, have a few more valve questions lol.
I was able to get the 0.038mm under the right intake valve, it has a lip on it or something because after it clears that it more or less fits in there, but then pulling it out it catches again.
Regardless, I figured that one and the left exhaust were probably > 0.03 considering I could get the .038 in there with some force so I wasn't going to do those two.
The other two I did manage to pull out (bending a few screwdrivers in the process) the left intake being a 2.60 and the right exhaust a 2.62
Would it be an okay move to just go with the 2.55 for both? It might make the right exhaust a tiny bit over spec...would that be an issue?
Also, not very understanding of valves and such, but is it bad to have them mixed with some being right on the edge of tight, and the other 2 right on the edge of loose? Just figured that if I bumped the two the 0.038 fit under down by 0.05 it would be a touch too far on the loose side.
Thanks,
Wright.
Either company will be fine.If you have 2.60 and 2.62 on the exhaust I would run 2.50 to keep from having to change them in another 3000 to 4000 miles. .08mm to .12mm is good on the exhaust and on the intake I would shoot for .05mm to .08mm.The pulling and catching on the feeler, is most likely due to the shims being dished ever so slightly, and the feeler gauge makes that bend as it travels between the shim and cam lobe.
Quote from: ben2go on July 17, 2011, 08:14:52 PM
Either company will be fine.If you have 2.60 and 2.62 on the exhaust I would run 2.50 to keep from having to change them in another 3000 to 4000 miles. .08mm to .12mm is good on the exhaust and on the intake I would shoot for .05mm to .08mm.The pulling and catching on the feeler, is most likely due to the shims being dished ever so slightly, and the feeler gauge makes that bend as it travels between the shim and cam lobe.
Crap, since the feeler traveled under the right intake and left exhaust I didn't pull those, so I don't know the size. Those were the measurements for the left intake and right exhaust.
I might just go with the 2.55 on each just so I will be forced to change them soon, in which case I can do all 4. Life...
-Wright