Ok, so I had some issues with the carbs not running right. I cleaned them out, replaced the small little O ring, gave the edge of the diaphragm a bit of oil, a touch on the o ring, cleaned all the jets, put a little oil on the sides (I had one stick) and put new screws on the carb bowls, oh and one new float ring. Now it runs great but here is the problem it idles at 3k. I adjusted the idle screw with no avail, its at the lowest point.
When I start up the bike, it starts up fine, runs at 1.5k and if I give it some gas it responds promtly. If I add choke, it bogs, to where if I add too much I can kill the engine.
Conversely, when its warmed up, it idles at 3k, but if I add some choke, it will go as high as 5k at its maximum choke.
Whats going on? I cant figure this out???
I thought it was the throttle cable being set too high, but I adjusted it to the lowest setting as well. I'm not sure whats going on, some one help!
adjust the throttle cable at the carbs?
check the carb boots to make sure they are on there flush. top and make 100% sure on the bottom.
air box side likes to be a pain on the bottom.
also.
adjust your idle screw after riding the bike a bit when its properly warmed up awhile, not when its cold.
Air leaks around the intake boots/airbox or filter/ exhaust manifolds? Idle mixture screws turned for your appropriate system? Valve clearances? Vacuum caps all in place? Float height correct?
Could be any of those. Check one at a time until it runs correctly.
adjust the throttle cable at the carbs?
Did that
check the carb boots to make sure they are on there flush. top and make 100% sure on the bottom.
air box side likes to be a pain on the bottom.
Pretty sure, everything is flush, but I will check
also.
adjust your idle screw after riding the bike a bit when its properly warmed up awhile, not when its cold.
Did that
Valve clearances? Vacuum caps all in place? Has 4k miles on it, should be fine
Float height correct?
I will check this, but I don't think this problem will manifest because of this. Flooding maybe?
Could be any of those. Check one at a time until it runs correctly.
Try disconnecting the throttle cable completely and starting it, see where it idles then. They can get hitches in them easy and you won't even notice unless you disconnect it completely.
Quote from: stafebak on July 27, 2011, 07:51:46 PM
Try disconnecting the throttle cable completely and starting it, see where it idles then. They can get hitches in them easy and you won't even notice unless you disconnect it completely.
I did this when I was adjusting the cable, seemed like it ran fine and choked as usual, but this was when it was cold. I wouldn't see why it wouldn't do the same thing when it was cold or warm.
Float can cause it to idle high, if it is low.
Throttle stuck open or lean.
Cool.
Buddha.
Quote from: dsmgs500 on July 27, 2011, 07:23:31 PM
Valve clearances? Vacuum caps all in place? Has 4k miles on it, should be fine
Float height correct?
I will check this, but I don't think this problem will manifest because of this. Flooding maybe?
Could be any of those. Check one at a time until it runs correctly.
4000 miles, it is past due for a valve adjustment.They should be checked and adjusted every 3000 miles.The valves will tighten up and cause problems that appear to be carb problems.
wouldn't all these problems manifest all the time if it was a float bowl isssue or a valve issue? It seems like it acts differently at different points in time.
Carbs synchronized?
Is the choke cable out of its housing on the right carb ('89-00 models)?
Valve adjustments and oil changes and carb vacuum synchronization should be done every 4000 miles, per the manual.
Can some one explain what a high idle is caused by? Is it too much fuel? Or too much opening in the throttle plates?"
Also does the choke, allow more fuel or more air in?
Quote from: ben2go on July 28, 2011, 08:10:42 AM
Quote from: dsmgs500 on July 27, 2011, 07:23:31 PM
Valve clearances? Vacuum caps all in place? Has 4k miles on it, should be fine
Float height correct?
I will check this, but I don't think this problem will manifest because of this. Flooding maybe?
Could be any of those. Check one at a time until it runs correctly.
4000 miles, it is past due for a valve adjustment.They should be checked and adjusted every 3000 miles.The valves will tighten up and cause problems that appear to be carb problems.
Oh the reason I dont think its valves, is because before I cleaned it and replaced a bunch of stuff, it choked and ran find before my slide got stuck
You cleaned the carbs, good, now they are sensitive enough to point out that you need a valve adjustment.
Every time you touch the carbs, you should re-synch them.
Every time you do a valve adjustment, you need to synch the carbs.
Quote from: dsmgs500 on July 28, 2011, 11:35:49 AM
Can some one explain what a high idle is caused by? Is it too much fuel? Or too much opening in the throttle plates?"
Also does the choke, allow more fuel or more air in?
All of the above can cause high idle.Also a lean condition can cause the engine to fail to return to idle.Are you sure your pilot jets are clean and flowing properly?The orifice in the pilot jet is so small that a little varnish in there will cause running problems.
Quote from: scratch on July 28, 2011, 01:34:02 PM
You cleaned the carbs, good, now they are sensitive enough to point out that you need a valve adjustment.
Every time you touch the carbs, you should re-synch them.
Every time you do a valve adjustment, you need to synch the carbs.
I back this 100%.
My guess is a tight exhaust valve. The valves on my GS gets tight every 3000-5000 km.
Quote from: ben2go on July 28, 2011, 05:48:46 PM
Quote from: dsmgs500 on July 28, 2011, 11:35:49 AM
Can some one explain what a high idle is caused by? Is it too much fuel? Or too much opening in the throttle plates?"
Also does the choke, allow more fuel or more air in?
All of the above can cause high idle.Also a lean condition can cause the engine to fail to return to idle.Are you sure your pilot jets are clean and flowing properly?The orifice in the pilot jet is so small that a little varnish in there will cause running problems.
I cleaned it twice acctually, first time I did a bad job, second time I dissasemabled everything, and also got a wire brush and stuck it into the holes
Quote from: bombjack on July 29, 2011, 03:55:32 AM
My guess is a tight exhaust valve. The valves on my GS gets tight every 3000-5000 km.
are exhaust valves hard to do?
Quote from: dsmgs500 on July 29, 2011, 07:23:14 AM
Quote from: bombjack on July 29, 2011, 03:55:32 AM
My guess is a tight exhaust valve. The valves on my GS gets tight every 3000-5000 km.
are exhaust valves hard to do?
They are very easy to check (30 minutes top), but can be a bit tricky to adjust.
If they need adjustment then buy the valve adjustment tool. It saves you a lot of frustration when getting the shims out.
I was going to post Kerry's valve adjustment vid but appears to be gone.
Quote from: ben2go on July 29, 2011, 09:08:53 AM
I was going to post Kerry's valve adjustment vid but appears to be gone.
http://video.google.com/videoplay?docid=-2015554469142545363 (http://video.google.com/videoplay?docid=-2015554469142545363)
Quote from: bombjack on July 29, 2011, 09:11:47 AM
Quote from: ben2go on July 29, 2011, 09:08:53 AM
I was going to post Kerry's valve adjustment vid but appears to be gone.
http://video.google.com/videoplay?docid=-2015554469142545363 (http://video.google.com/videoplay?docid=-2015554469142545363)
Yep and I get nothing but a list of vids.Kerry's video doesn't come up.
Quote from: ben2go on July 29, 2011, 09:16:15 AM
Quote from: bombjack on July 29, 2011, 09:11:47 AM
Quote from: ben2go on July 29, 2011, 09:08:53 AM
I was going to post Kerry's valve adjustment vid but appears to be gone.
http://video.google.com/videoplay?docid=-2015554469142545363 (http://video.google.com/videoplay?docid=-2015554469142545363)
Yep and I get nothing but a list of vids.Kerry's video doesn't come up.
That's weird. When I click the link, Kerry's video starts playing :dunno_black:
I just bought a 2000. Ran great when I picked it up, all freeway all the way home so I didn't notice anything. Road it to work the next day and the dreaded mystery high idle at times.. over a few days searched the forum and tried a few things. First I lubed and adjusted the throttle cable and gave it a little slack. Nope. Read about the seeming sensitivity to leanness, found out where the airscrews where, found a small screwdriver, checked and found that the PO had removed the screw covers. So I turned the screws in (with the carbs on, engine cold) and counted three turns, from the info on here, stock jetting (probably.. I didn't remove the carbs to check but everything else is stock) stock airfilter I set them at 2 turns and readjusted the idle, Bingo, mystery high idle at times gone! over the next couple days I fine tuned the idle speed, first it was a bit low after the commute, then just a bit high then you guessed it, just right.. I like it a bit higher than the recommended 1250RPM though. Yeah it seams these bikes are really sensitive to carb adjustments.. When I get a chance I want to get the jet kit to richen it up just a tad, I hear it helps A LOT. Ed
were are these airscrews you speak of?
On the very bottom of the carbs, at the front of the float bowls, right in the middle of each carb bore. Using a small flatblade screwdriver pointed straight up you can just barely adjust them without removing the carbs (if the little caps that cover them from the factory have been removed). Ed
Quote from: dsmgs500 on July 29, 2011, 12:19:15 PM
were are these airscrews you speak of?
Read through my write up will help explain where everything is on the carbs. http://gstwins.com/gsboard/index.php?topic=56601.0
so list of things to go through from easiest to hardest
1. Rubber seal check
2.Airbox rubber seals
3.Throttle linkage
4. choke linkage
5.Mixture screws
6.valve adjustment
am I doing this right? Missing anything?
Quote from: dsmgs500 on August 01, 2011, 12:19:28 PM
so list of things to go through from easiest to hardest
1. Rubber seal check
2.Airbox rubber seals
3.Throttle linkage
4. choke linkage
5.Mixture screws
6.valve adjustment
am I doing this right? Missing anything?
Considering you've already done everything else, I say start with the mixture screws.
First turn them both down all the way. Turn down the idle screw as well. Then turn out 1 turn, start the bike.
Test.
It'll probabably stall and shut off. Then turn the screw a bit more, closer to two turns.
Test.
It'll probably hold the idle a bit better. Start adjusting the idle screw. If it doesn't go down further, shut off the bike. Turn the mixture screw out a bit more.
Test.
Keep doing that until you find your sweet spot. Remove plugs accordingly to see where you are at.
Good luck!
Add carb vacuum balance/synchronization
Any news on this?
I had the same exact problem with my bike! A valve adjustment followed by a carb sync fixed that right up :D
-Katlynn
I haven't worked on it yet, I will try to get some work in today.
I did take the plugs out. My left side looks whiter than my right side. Left is a bit chalky,right is chocolately. Does that say anything?
Quote from: dsmgs500 on August 08, 2011, 01:53:34 PM
I haven't worked on it yet, I will try to get some work in today.
I did take the plugs out. My left side looks whiter than my right side. Left is a bit chalky,right is chocolately. Does that say anything?
Lean on the left and rich on the right.Dirty carbs and possibly a plugged pilot jet on the left.
Quote from: ben2go on August 08, 2011, 03:31:38 PM
Quote from: dsmgs500 on August 08, 2011, 01:53:34 PM
I haven't worked on it yet, I will try to get some work in today.
I did take the plugs out. My left side looks whiter than my right side. Left is a bit chalky,right is chocolately. Does that say anything?
Lean on the left and rich on the right.Dirty carbs and possibly a plugged pilot jet on the left.
First time I cleaned them out, I didn't do a good job. Second time around, I used a wire brush and poked through all the holes, runs way better.
Could richening the side that is a bit more lean, solve my high idle?
also where is the carb sync write up? I can't find it
Here is the tool that most of us use.I fill it with red two stroke oil.
http://www.powerchutes.com/manometer.asp
Warm the engine so you don't need choke to start it.Set the idle to 1200rpm and shut off the engine.
Connect the hose ends to the upper vacuum ports.Make sure they seal tight.
Start the bike and watch the fluid.If your carbs are sync'd/balanced then the fluid will remain at the same level.
If not, locate the balance adjustment screw between the carbs.Very slowly turn the screw in very small amounts.Watch the fluid in the tube.If it continues to rise as you turn,stop and slowly turn the other way.Very slight screw movements can really affect the carb balance.Your idle will change as the carbs balance.If the idle picks up,adjust it back down.If the fluid get sucked into the engine,don't freak out.Make a mental note of which cab sucked in the fluid and turn the screw a half turn the opposite direction,ie right carb sucked fluid then turn screw 1/2 turn to the left.Refill and restart the engine.Then try again.
(http://i205.photobucket.com/albums/bb17/ben_2_go/Motorcycle%20Stuff/Mikuni%20BST33SS%20Carbs/top-1.jpg)
FYI When I choke it, It bogs. Other than that it runs fine. Is that a clue to anything?
Quote from: dsmgs500 on August 11, 2011, 11:24:29 AM
FYI When I choke it, It bogs. Other than that it runs fine. Is that a clue to anything?
After the bike sets overnight,do you have to use the choke to start it?After the bike has ran or been rode,then no choke should be needed, unless the bike has sat for a few hours and cooled off completely.After my first start,I never need the choke again for the day.
I don't need choke to start it up when its cold :dunno_black:
I just tried to carb sync it, its not working, one side sucks up all the fluid, I have backed out the screw, and then put it all the way in, right side still keeps sucking it all up.
Edit: I got it to run, its balances on choke but not with out :dunno_black:
Quote from: dsmgs500 on August 11, 2011, 12:47:00 PM
I just tried to carb sync it, its not working, one side sucks up all the fluid, I have backed out the screw, and then put it all the way in, right side still keeps sucking it all up.
Edit: I got it to run, its balances on choke but not with out :dunno_black:
It sounds like a valve out of adjustment and one side isn't getting enough vacuum.
I got it adjusted finally, carb balanced, and the idle screw set. Sounds alot better, going to take it for a ride see how it feels. The choke still works sporadically. Will report back in a few.
OK so it sounds good now, provides more power down low and has more growl. I balanced the carbs when it was warm and now it see like its running alot better. I am about to pull out the plugs and see how they look.
Only issue it has right now is that, when I put the choke down, it doesn't really do anything other than bog a bit untill I give it throttle and hold it for a bit. Then it will hold the high revs. What does this sound like?
You have'nt checked the valve clearence yet, have you?
Quote from: bombjack on August 12, 2011, 11:09:22 AM
You have'nt checked the valve clearence yet, have you?
I don't have the correct tools to do that yet
You will know more after the valve clearance check and adjustment.After you do this,you will need to re sync the carbs.Every time the carbs are worked on or the valves are adjusted,it alters the vacuum signal enough to throw the carb balance back off.