Hey everyone,
Figured I'd make my first post amazing, so here we go -
Forenote: The bike is basically new (~490 mi. when it was bought). It sat in storage for a while and wasn't properly taken care of.
Me and a friend went to clean the carbs and we chickened out half way (carbs weren't off) and replaced everything. The guides for GS500F carb removal are lackluster and we didn't want to continue blind. So, we put the airbox back in, plugged everything in, and went on our way. We replaced two weather-cracked fuel lines which solved a fuel smell that was fairly obvious. Along the way we did muscle the carbs around, but couldn't get them unseated, which was the point when we chickened out.
Now the bike has a problem it didn't have before. If I come to a stop the engine revs high with zero choke. However, if I do not touch the throttle as I'm coming to a stop the engine will idle around 1,200-1,500 RPM (factory specs). It's only after I rev the engine does the engine RPMs go up and stay around 3,200. Interestingly enough I can bring the engine speed back down to regular idle by feathering the clutch for a second. During riding the bike doesn't seem to be riding in a higher RPM range than usual. However, at the stop lights I can consistently reproduce this problem.
My first instinct is that I'm pretty sure we placed the fuel lines wrong. It runs in RES and lags to a stall in ON and since RES is where PRI is run from, it should run from there. I'm going to swap them after I'm done typing this. Which fixes that problem.
As far as the problem is concerned it doesn't seem to have any indications of a intake leak. The idle doesn't stay high at all. It will come back down after feathering the clutch and stay steady after that. It's only after I blip the throttle at a stop will it stay high like it's choked, even though the choke is fully off.
Second thing I'm almost positive I eliminated is throttle stick. The throttle is very responsive and if I try to get the bike to jet off the stop line when the idle is high it will die unless I actually twist the throttle to keep engine speed up.
The only two things I'm not certain of is if the choke is potentially stuck a little open, or the choke needs adjustment. Likewise, I'm curious whether or not adjusting the idle when I blip the throttle so it goes back down to normal would be beneficial at all or it would just lead to a stall unless I'm constantly blipping the throttle.
I also would wager it could be the air valve under the gas tank getting loose, but I'm not certain if that would cause this or not. I know there's a vacuum hose on the left carburetor, but I haven't checked it. I'll check it tonight when we take off the tank.
Does anyone have any experience with this? I'd rather not have to order a Hayne's manual and work my way through a full carb rebuild if I don't have to. I'd really appreciate any feedback, I'll be more than happy to test any suggestions or go out and test different things to give you guys a better idea of what's wrong.
Thanks!
Lube your throttle and choke cables for now- just wd40 or something will work better than nothing.
And did you take the float bowls off yet? If not, do that and clean them at least.
I haven't. Took it out for a ride today -
Checked the tank. Everything is plugged in correctly. Idled perfect for the first probably 45 minutes of it being on. No problems at stops or anything. It appears after about an hour of riding the idle gets progressively higher, peaking at around 3,700. This isn't a big deal, except I went into a few turns today with the bike's engine speed definitely too fast. I don't encounter this problem when I have to downshift but for a quick turn in the same gear this is very evident. It's almost too dangerous to ride it unless I take turns at granny speeds once the idle starts getting bad. All the plugs are plugged in correctly and there are no visible air leaks. I would think that an intake leak would be present at all times, and not just after being on the road for an hour or so. The only thing I could think of now is a rotted o-ring or something that does it's job cold but once it starts expanding it screws everything up.
I don't know anymore. Could it be a misadjusted choke/throttle from when we moved the carbs and cables around a bit before reseating them?
When I was riding home I was able to take my hand off the throttle and have the bike essentially ride itself in first. Which is really bad. To me, that's the only symptom of a sticky throttle even though the throttle snaps and has a normal amount of play at the handle bar.
I really don't want to have to take it to a dealer. It's probably gonna be well over 500 dollars for the entire thing with all the added "magical" problems the dealers create to make money, which means I'll be boxing up my bike until I can afford to take it in on a college kid's salary. Let me emphasize I really don't want to do that.
Only other thing I can think of is the carb boots are warming up and expanding (causing an air leak).
Quote from: Big Rich on August 25, 2011, 10:12:50 PM
Only other thing I can think of is the carb boots are warming up and expanding (causing an air leak).
I wish that I could find OEM carb boots. I can't find any anywhere. I had the same suspicion.
We did yank on the carbs a little to try to unseat them and they didn't 'seem' to budge, however, it may have been enough to unseat them. We didn't bother to push them back in at all because they didn't seem to move. Unfortunately this problem occurs way late into the ride so it makes it hard to check for the leak. If you have a suspicion this could be the problem it would be fairly trivial to take the bike down again and push the carbs in as hard as we possibly can while tightening them.
go for a long hard ride for 20-40 mins... then re-adjust your idle down to 1100-1200. If that doesn't solve your issue then grow some balls and pull the carbs. They should come off easy enough push them down and pull up a few times and the heat bond should break. Pull off your float bowls and check for gunk pull out the 3 jets from each side and blow them out. Take the carb boots off the head and check for major cracks. while you got all that crap taken apart grab some starter fluid and put the little straw into the 2 holes under the carb intake and blow those bad boys out. throw it all back together, prime it check the float levels. Reset your idle after another longer ride. If that doesn't fix it, grab the starter fluid and cover the entire engine and light it on fire...
Really, pulling carbs off isn't as scary as it seems. I had the same sentiment you have now before I took them off and cleaned them, but really if you're careful, do 1 at a time, and make sure you have everything pulled correctly it's not too bad. My fears derived from it being such an important part of the bike, one of the parts that can cause all sorts of gremlins, and my lack of experience. But with the guides here (search is your friend) you can accomplish taking the carbs off and cleaning them.
And if you run into any questions, pretty much everyone here has done it 1 time or another so just ask.
I don't know why you wouldn't want to get the Haynes manual...........go for it and it will help walk you through a lot of things on the bike..........definitely recomended.
If you pull the carb, drill the brass caps and adjust the pilot screws. If they are out of adjustment it can lead to your hanging idle problem.
-Jessie
Quote from: crzydood17 on August 26, 2011, 02:30:03 AM
go for a long hard ride for 20-40 mins... then re-adjust your idle down to 1100-1200. If that doesn't solve your issue then grow some balls and pull the carbs. They should come off easy enough push them down and pull up a few times and the heat bond should break. Pull off your float bowls and check for gunk pull out the 3 jets from each side and blow them out. Take the carb boots off the head and check for major cracks. while you got all that crap taken apart grab some starter fluid and put the little straw into the 2 holes under the carb intake and blow those bad boys out. throw it all back together, prime it check the float levels. Reset your idle after another longer ride. If that doesn't fix it, grab the starter fluid and cover the entire engine and light it on fire...
I have a can of Berryman's B12 I can spray into the carbs from the airbox. However, my fear here is that the idle adjustment will cause my bike to die without tons of choke except for when it's super warm (30-40 min later). This seems more like a bandaid than a fix. But it's worth a shot if nothing else works.
Quote from: justinmc84 on August 26, 2011, 06:31:44 AM
Really, pulling carbs off isn't as scary as it seems. I had the same sentiment you have now before I took them off and cleaned them, but really if you're careful, do 1 at a time, and make sure you have everything pulled correctly it's not too bad. My fears derived from it being such an important part of the bike, one of the parts that can cause all sorts of gremlins, and my lack of experience. But with the guides here (search is your friend) you can accomplish taking the carbs off and cleaning them.
And if you run into any questions, pretty much everyone here has done it 1 time or another so just ask.
Most of my fear isn't taking off the carbs and ruining something. We ended up chickening out mostly due to the dry rot on alot of the tubing. I didn't want to tear something and brick my bike for a few weeks while I scour the internet for a 2006 GS500F carb rebuild kit and a carb disassembly manual. The one off the GStwins website is the one we tried using, but it's not very descriptive, and I'm pretty sure the Mikuni carbs on the newer models are different.
Syncing the carbs seems easy enough. Not that I want to do it yet, but I may as well ask the question now. Are the two valves on the top of the carbs not hooked up to the upper T (the two valves that are left open) the adjustment valves? I understand you sync them by vacuum, and most newer carbs have specific adjustment valves that you can plug in to. On my bike these valves I speak of now have no covers and both face the left on the top of the carbs looking down from the gas tank side. I also understand the screw-looking thing between the carbs is the adjustment screw, and you twist it either way until the vacuums are even.
If the fact the left side upper valves aren't hooked up vs. the right side upper valves (right side has the T connected to it) as I stated above could be considered a problem - let me know and I'll get the digital camera out and take a picture when I get home from work for clarification. I could be describing it all wrong.
My 2004 GS500F has your exact same idle problem - it revs high at 3200 rpm after it has warmed up. It goes to 1100 rpms when you first take it off choke, then, by itself just sitting there, after about six or seven minutes, it slowly climbs to 3200 rpm. When riding around, it usually idles at 3200, but sometimes, it will idle down to 1100. :dunno_black: I have gotten used to it, but should get it fixed. Please post your fix to your idle problem when you get it all sorted out.
changing the idle down to 1100-1200 after its completely warm is in no way a bandaid its the correct and factory way to set a idle. If the idle is set just a bit too high it can cause a hanging idle...
Quote from: crzydood17 on August 26, 2011, 06:26:07 PM
changing the idle down to 1100-1200 after its completely warm is in no way a bandaid its the correct and factory way to set a idle. If the idle is set just a bit too high it can cause a hanging idle...
This is interesting. Would that "complete warm up" be that 45 minute mark? That would explain a lot. We've screwed around quite a bit with my idle. I have no doubts I need to clean my carbs, but this could definitely be possible.
Good news though guys,
Today I rode the bike around with my girlfriend for about 30 minutes, started getting the hanging idle problem, took her back to the house and shut down and restarted the bike. Held it's idle at 1,500 and I took a WD40 can (which is apparently safe on rubber) and sprayed around the intake manifolds (engine side) and paid attention for changes in engine sound. Re-revved the bike so it hung and then sprayed again. Nothing. Sprayed a few areas around the location where the carbs and the boot are locked in by the clamp and nothing. No engine changes. I'm thinking this rules out a intake manifold leak. Especially considering WD40 is flammable it should've caused at least a minor increase in engine speed briefly. When we open up the bike again tomorrow I will spray more thoroughly and try to spray the air hoses as well as the manifolds leading to the airbox. But so far, nothing.
We're going to tackle the problem like this
Adjust throttle -> Adjust Idle (as suggested) -> Adjust choke (if it's stuck) -> Remove the tank and spray WD40 looking for leaks -> etc.
If the idle/cable adjustments fix it, we'll probably tackle the carb problem with some Berryman B-12 ChemTool and then pursue a more permanent fix once my Hayne's manual arrives. Otherwise, I'll be continuously updating this thread until the problem is solved.
I'll post things as I go, but I'd appreciate feedback from the more experienced members. It would be a great help knowing I'm approaching things the right way.
Quote from: lamahug on August 26, 2011, 06:23:04 PM
My 2004 GS500F has your exact same idle problem - it revs high at 3200 rpm after it has warmed up. It goes to 1100 rpms when you first take it off choke, then, by itself just sitting there, after about six or seven minutes, it slowly climbs to 3200 rpm. When riding around, it usually idles at 3200, but sometimes, it will idle down to 1100. :dunno_black: I have gotten used to it, but should get it fixed. Please post your fix to your idle problem when you get it all sorted out.
The documentation on the gs500 wiki regarding the 04-08 GS500FK's is severely lacking. I plan on documenting everything I do.
Double post - damn internet. Mod please delete this one.
Watch what you do with Berrymans- it, like most carb cleaners, can damage rubber.
While a complete carb tear down is always best, I think the majority of your problems are just in the float bowls and jets. All of which can be removed and cleaned with the carbs still on the bike.
Quote from: Big Rich on August 26, 2011, 07:06:08 PM
Watch what you do with Berrymans- it, like most carb cleaners, can damage rubber.
While a complete carb tear down is always best, I think the majority of your problems are just in the float bowls and jets. All of which can be removed and cleaned with the carbs still on the bike.
Would you happen to know of any guides on properly adjusting the choke/throttle cables and how to insure that they aren't getting binded anywhere from when we moved them to access the carbs/airbox?
Before we try adjusting the idle or anything involving removing the gas tank, the first thing we're going to do is adjust the cables.
Not for a GS500- I don't own one........
Why do you want to adjust the cables? Aside from a sticky cable that I mentioned earlier (which I don't think is an issue anymore), there shouldn't be any need to at the moment. I stick to my prior advice about the float bowls and jets.
Quote from: Big Rich on August 27, 2011, 05:50:42 AM
Not for a GS500- I don't own one........
Why do you want to adjust the cables? Aside from a sticky cable that I mentioned earlier (which I don't think is an issue anymore), there shouldn't be any need to at the moment. I stick to my prior advice about the float bowls and jets.
I guess it's because I don't see why the problem wouldn't exist all the time if the carbs and jets were really screwed up. Shouldn't it idle high/run lean all the time if the jets and float bowls are messy?
Don't take this as me doubting your advice. I'm just having trouble visualizing why the problem isn't consistent from the start. More for my learning so I can spot this problem easier if it is indeed it.
Have you taken it for a longer ride then adjusted the idle afterwards? That's probably the fix.
Like I said- I don't own a GS. But my GR's don't take anywhere near 45 minutes to get fully warmed up. That's why I think you need to clean the carbs. You said the bike sat for a while (gas starts to go bad in as little as 3 weeks) and you said the bike has low miles (which is why I haven't said to check the valves). If you don't want to pull them off completely to do it, fine. Most of the problems you will have are in the jets and/or varnish in the bowl.
The most usual problems with cables are apparent when you turn the handle bars. If the engine speed increases but lowers, it's your throttle cable. If it increases and stays, it's the choke cable.
Well I started running some Berryman's B12 through it.
The gas bubbling part scared the living f%$k out of me. It's supposed to do that though I guess, Berryman's eats up the styrene in the gas.
New problems have arised though and I can't diagnose them as me needing to adjust my idle because the carbs are cleaner, or my bike exhibiting more signs of dying.
Took the bike out for a ride yesterday. Ran fine. Idled a little low but the hanging idle problem still existed.
Took the bike out today. Didn't let it warm up enough, around 5 minutes. The ambient temp is about 95 degrees, I figured it was fine. Got bored and decided to joy ride it around the block a bit to warm it up at about 1/2 choke. The bike started backfiring like mad. If I revved the throttle I'd get one or two and then it would stop. During idle it didn't backfire at all. I noticed the choke's RPMs at full-open were 1k less than normal (it would normally choke at around 4-5k).
Let it rest a minute and then went back to riding. Took it on it's first turn after being fully warmed up (~10 minutes later) and the bike died in the turn. Sputtered, popped once or twice, and died. Restarted it and made my way home. The throttle didn't seem unresponsive, however the acceleration was noticeably deadened. It started to act "normal" by the time I arrived home. There was no popping on the main roads, the bike seemed responsive until I released the clutch as I began my turn at which point the bike would seem to loose forward momentum and no amount of throttle would get the bike to speed up quickly. This being said gunning it in the straights was easy.
This sounds like the bike is really lean now. I'm thinking it's for sure an intake leak, and it's getting worse by the day. I'm almost 100% certain the berryman's didn't cause this because I ran it for two days with berryman's in the tank and didn't have a problem at all. I checked the tank, and judging by the miles I have on the odo so far (~60 since the last fill) and the average I get (~150 per fill) I'm still just a hair over 1/2 full. I followed the berryman's by the book, ~1 oz per gallon of fuel and I added about 2.5 oz to a tank of 3.5 gallons.
I'll take it out for a short run tomorrow. If it doesn't fix itself I'll start calling mechanics around town. Figured I can't lose, if it's any more than 600 dollars to repair I'll just do it myself. Just wish I could've got a few more months into my favorite season (Winter) before I had to come to something like this. As for the carb boots needing to be replaced (highly likely) - are item numbers 20, 21, 22, and 23 (http://www.bikebandit.com/2006-suzuki-gs500f/o/m9752#sch508462) what one would consider the carb-head boot? I'm almost 100% certain they are, but I'd rather ask here than spend 40 bucks in vain.
Man, I wish I knew how prone this motorcycle was to problems before I bought it...I hope you find a fix
Quote from: rayshon on August 30, 2011, 05:42:57 AM
Man, I wish I knew how prone this motorcycle was to problems before I bought it...I hope you find a fix
The GS500 is Not prone to problems. However, if a PO messes with it and doesn't know what they are doing and then messes some more, then a subsequent owners starts chasing their tail trying to fix what should have been left alone in the first place. Then the new owner can feel the bike is prone to problems.
As to your other thread... adjusting the valves is not going to be costing you money out the ass. You have two options. Follow the instructions previously posted and do it yourself - or - throw your hands in the air, bend over and take it right royally as some mechanic ass rapes you over the valve adjustment and your lack of willingness to do it yourself.
Michael
Quote from: mister on August 30, 2011, 06:20:29 AM
Quote from: rayshon on August 30, 2011, 05:42:57 AM
Man, I wish I knew how prone this motorcycle was to problems before I bought it...I hope you find a fix
The GS500 is Not prone to problems. However, if a PO messes with it and doesn't know what they are doing and then messes some more, then a subsequent owners starts chasing their tail trying to fix what should have been left alone in the first place. Then the new owner can feel the bike is prone to problems.
As to your other thread... adjusting the valves is not going to be costing you money out the ass. You have two options. Follow the instructions previously posted and do it yourself - or - throw your hands in the air, bend over and take it right royally as some mechanic ass rapes you over the valve adjustment and your lack of willingness to do it yourself.
Michael
He's right, the Gs500 is a reliable bike. The only downside is it's air cooled, which I learned overheated a LOT faster than I had originally thought.
My problem is regardless of what my actual problem is there are so many "nickel-and-dime" problems that need permanent solutions that I'll be spending 300 bucks myself to finish it. Rebuild kits for older (< K4) models go for around 75 bucks, so I'd imagine if I could find a rebuild kit for my bike (2006 GS500F) it would cost the same x 2 (one for each carb). Then, I need to buy vacuum hosing and start replacing all of the hosing involved in the intake as a precautionary measure, and then finally replace the boots on the carb-head connection (which I can't find, I hope someone can identify them in the previous diagram I posted) which will be another $80. It's a good project, and with the Haynes manual finally arrived I can tackle it slowly probably.
The only reason I'd want to pay a dealer is if it's cheap enough to just get done there, where parts are at cost. Otherwise, I'm mainly going to take it to a dealer to have them tell me what is REALLY wrong so I can tackle that first instead of taking the trial-and-error approach and replacing everything.
My case is exactly like you said. The POS PO (har) didn't take care of the bike at all. It ran fine when he brought it for a test ride, started up cold great, didn't leak, everything checked out you're supposed to check out on the bike before you buy it, and then BAM this all happens.
EDIT:
Bike ran fine tonight. It was weird. Throttle is a little out of adjustment. Stalled it a few times until I realized it. Idled solid, sounded solid, no popping, even the choke at full was choking at where it normally should be. This is by no means a fix, but I'm thinking the B12 is starting to work. Could the popping have been because of the B12 cleaning out the varnish and the varnish made the mix temporarily rich?
If your vacuum hoses are in such a bad state ,check to see that rubber cap on left carburettor vacuum line is still there with its wire clip,as this blanks this port off as its not generally used.
The B12 didn't make the fuel rich or lean; it is basically a concentrated fuel detergent additive. Some / most carb / fuel injector cleaners also tend to raise the octane rating a bit; put in a lot of it and you'll smell it coming out of the exhaust when the engine is running. Put in too much of it and the engine won't even fire...
My best guess is that the detergent is soaking some of the crud off the carb guts; it only works when it is given time to soak the components. There are those who add carb cleaner and immediately ride the bike until the tank is empty, then complain when the carb cleaner has little or no effect. I don't understand that logic; if you consume the carb cleaner by running the engine, how can it clean anything?
Odds are that you're on the right track here; cleaner carbs will help you narrow down the other problems to help identify the culprits. Don't use too much carb cleaner in the gas, or you'll find yourself draining the tank; as I mentioned previously, too much carb cleaner will make the engine difficult or even impossible to start, so a few ounces per tankful is the way to go. The most you can probably use is one or two ounces per gallon of gas; after you exceed that amount, you risk making the fuel non-combustible. Use it sparingly at first and pay close attention to any changes; as you gain experience using it, you'll have a better idea of how much is too much. Personally, if I can smell it in the exhaust, I know I've overdone it, so I add gas to dilute the cleaner.
I advise people to add it to the tank, run the engine for a few minutes to get some of the detergent into the carbs, then shut the engine off and let it sit for 24 to 48 hours. Doing that will allow the cleaner time to remove some of the crud from the guts; then run the engine, and if possible, take a short shakedown ride to see what effect the carb cleaner has had. After the ride, let the bike sit another 24 to 48 hours, then test it again. When the gas gets low, refill the tank and add three more ounces of carb cleaner; then give it time to soak the carbs again.
This isn't rocket surgery, or brain science; you seem to be making progress, which is encouraging. As you've seen first hand, fuel-additive carb cleaner can really help to improve runability. Carb DIP is a different animal; it eats plastic and rubber parts and can even remove paint. The fuel additive type is much safer to use, and as you've seen, the results can be impressive.
One last thing you should consider; air-cooled engines DO tend to run hotter than those which use liquid cooling, which is why proper rejetting is so critical to an air-cooled engine. The extra fuel provided by proper rejetting keeps combustion temps lower than an engine which is running in stock / lean condition, as delivered from the factory. Emissions requirements determine the jetting as-delivered; it is up to the owner to make the needed changes to prolong engine life.
Yes, I KNOW that many people ride motorcycles that have never been rejetted; I'm not one of them. All things considered, the GS engine is incredibly tolerant of being run lean, which is a tribute to the original designers. However, once the limits of the engine design are reached, bad things happen rather quickly, which is why so many people are forced to rebuild or replace their engines. Of course, some owners decide not to replace or rebuild their engine, so the remaining usable parts end up being sold to someone else, which makes the parts-whores happy. I'm not knocking the parts-whores; if I had the money, I'd be the worst one in the universe... which I suppose makes me a parts-whore wanna-be...
Keep punching; I think you're doing fine, and I suspect you'll be back with more good news for us as you correct the problems you encounter.
EDITED to correct typos and brain-misfires
I have had this same problem since day one of this bike 3 years ago, was told in other threads it was normal. I have rebuilt the carbs, jetted it, still I have the hanging RPM's when I come to a stop after being warmed up and running for a few miles. I have learned to just feather the Clutch a little and let the RPM"s go back to normal or I gear down completely as I come to a stop. I have found it is worse when you come to a quick stop as apposed to fully gearing down to a stop. I finally stopped worrying about it and enjoyed the ride.
Once this whole mess is completely solved I plan on installing a Yoshi TRS slip-on and a K&N Air Filter on the bike to give me a reason to get back under it and swap out the jets. The wiki has jetting information for performance parts, so I'll probably end up going off that. Hopefully the bike won't run that lean after. Right now it's not a big deal, but that makes sense why the GS overheats quicker.
Next on the list though is changing out the oil and spark plugs even before the above. The spark plugs are probably worn a bit from sitting for so long and the oil is definitely old. It's at the first break-in milestone anyway. I'll install some Iridium plugs and nice oil and be well on my way to a better running engine after all this is done.
Anyway, once I get off class/work I'm going to take it out for a longer ride (~1-1.5 hrs.) and put it through it's paces. I'll update you guys on my findings then.
EDIT:
Today's trip was about 10 miles and 25 minutes longer than yesterday's. It acted a bit weird when it started. I started it with choke and it choked at about 2k, let it sit and then blipped the throttle and the choke shot up to 3k, let it sit and blipped it one more time and it was normal. Is this how it can be? It seemed to be real cold blooded today. Engine popped a few times, I'm thinking every so often it misfires and doesn't burn all the fuel which leads to the pop.
As the ride went on the bike handled better and better. Throttle response was fine after warming it up for about 10 minutes, and then riding with the choke on at about 1/2 for about a mile, and then bringing it down to a 1/4, before turning it all the way off about 10 minutes into the actual ride itself. The bike idled at stop lights just fine (Sat around 1,300) , very little popping (only heard one pop the entire ride) and everything sounded good. No knocks or pings and the engine at idle fully warmed up was running what sounded to be nominally.
About 40 minutes into the ride I started blipping the throttle at stop lights to try to get the idle to hang. Nothing. Blipped the throttle hard (revved it to 6k) and then watched it drop all the way back down to idle quickly with no real stopping. The only remarkable event was that the idle hang a little bit during one rev "cycle" at the light while I was waiting. But I was unable to reproduce it so I dismissed it as an anomaly.
The throttle decel cable is definitely in need of adjustment. Even the throttle snaps shut (implying no kinks or problems in the cable itself) it was very easy for me to accidentally be barely on the throttle enough to rev the engine. Got it home, shut it down, restarted it in the garage and blipped the throttle a few times to check again for the hang. GONE! A few more days and I'll dismiss the hanging idle as a solved, probably caused by a clogged idle circuit or something.
What it sounds like is the next pursuit is to check my spark plugs and change my oil. Oil is old and probably full of metallic stuff from the breaking in I've been doing. Plus it's about time for it's "dealer-grade" break-in service (it's got 807 mi. on the odo now). This weekend I'm going to investigate the spark plugs looking for warping. Since the bike was sitting for so long it's possible the spark plugs are bad, which could be causing the misfires when it's cold. It is almost certain the oil is really old. The battery may be going sour too, so I'll probably replace that in the next couple weeks as well around the same time I replace the spark plugs.
Once again, I'll check back in when I ride it again, and then again when I check the spark plugs. Even if they're good I'll probably be replacing them with NGK iridium's for safety sake.
Bumping:
This week I changed the oil (Motul 5100), put in a K&N KN-133 oil filter, and swapped out the spark plugs with the NGK regulars. Bike fired up and ran like a beast. I was so happy. Spark plugs indicated normal wear. Not running to lean or too rich.
Drove the bike to work today, noticed the idle acting wonky. On the way home getting off the highway the idle stuck at around 3.5K-4K and would do exactly like it used to. The day was rather hot and the bike almost overheated due to it. Interestingly enough at one point I could use the clutch to bring the RPMs down using some engine retardation, but if I fully depressed the clutch the RPMs would reclimb to 4k (about where it chokes at full). The bike wouldn't "drive itself" however, and would -eventually- slow down with the engine loaded. I tried replicating the clutch causing the RPMs to rise steadily to 4k and could get it once or twice, and then it stopped doing it.
Anyone have any ideas? Any solutions on what could be done? As it stands over the winter I want to rejet my bike and throw a Jardine full system and a K&N lunchbox in there. Could this be a source of improvement? I'm 99.9% sure it's not a vacuum leak. As my previous posts say, I have already tested for it and found nothing conclusive and I find it hard to believe the vacuum leak would be intermittent.
My 2004 GS500F runs perfect except for a similar stupid intermittent high idle issue. I've put on 2800 miles this summer, and the GS500F runs perfect - plenty of power, good throttle response, no hesitation, no backfiring, etc...EXCEPT FOR THIS INTERMITTENT HANGING IDLE! :cookoo:
I believe that the carbs are OK, because the bike runs perfect. What about something that is causing the throttle mechanism from returning to the idle position, be it the throttle cables, or a broken spring, or there is hysteresis/friction in the throttle mechanism or some pin is sheared on the throttle plate shaft or the throttle plates are loose? So, there is a spring system that is responsible for putting the throttle back in the idle position - just let go of the throttle and it goes to idle. Is it returning to the correct throttle/idle position? How do you check that? I was looking for a way to check this - some shaft that one could mark and observe without tearing apart the bike. I couldn't see anything move when I moved the throttle cables.
When the high idle occurs (about 3500rpm) and I've stopped, I try to blip the throttle to get it to go back to idle. No luck at all. I rev it up pretty high (6K) and then just let go of the throttle, trying to 'snap' it back to idle - nope, that doesn't work either. The traffic light turns green and off I go, and at the next stop the bike idles fine (1100rpm). :dunno_black:
This upcoming winter, I will try and take the throttle system apart - I'll squirt WD40 in the throttle cables/carb shafts, and then see if one can measure the throttle plate positions. The bike needs new tires, it's oil changed, and possibly some new brake pads, so why not look at the throttle mechanism (it has 9000 miles on it)?
Quote from: Dr.McNinja on September 17, 2011, 04:31:36 PM
Anyone have any ideas? Any solutions on what could be done? As it stands over the winter I want to rejet my bike and throw a Jardine full system and a K&N lunchbox in there. Could this be a source of improvement? I'm 99.9% sure it's not a vacuum leak. As my previous posts say, I have already tested for it and found nothing conclusive and I find it hard to believe the vacuum leak would be intermittent.
Did you drill the brass caps and adjust the mixture screws yet? That adjustment being off can lead to the exact symptoms you are describing. It would be better to get your problems sorted out before you start modifying the bike (though a re-jet is generally necessary on a stock bike).
-Jessie
Quote from: BaltimoreGS on October 04, 2011, 05:56:06 PM
Quote from: Dr.McNinja on September 17, 2011, 04:31:36 PM
Anyone have any ideas? Any solutions on what could be done? As it stands over the winter I want to rejet my bike and throw a Jardine full system and a K&N lunchbox in there. Could this be a source of improvement? I'm 99.9% sure it's not a vacuum leak. As my previous posts say, I have already tested for it and found nothing conclusive and I find it hard to believe the vacuum leak would be intermittent.
Did you drill the brass caps and adjust the mixture screws yet? That adjustment being off can lead to the exact symptoms you are describing. It would be better to get your problems sorted out before you start modifying the bike (though a re-jet is generally necessary on a stock bike).
-Jessie
It's not. I fixed it by adjusting the idle when it was hanging at 4k. Phantom hanging idle is gone.