I cleaned my carbs and now have High Rev at Idel

[tsabadlk]

To start these are the specs for my carbs..

1980 GS850GT Carburetor Specs
Unit of Measurement = mm(in.)

Carburetor type = Mikuni BS32SS
Bore Size = 32 (1.26)
I.D. No. = 45110
Idle rpm = 1050 +/- 100rpm
Fuel Level = 5.0 +/- 0.5 (0.20 +/- 0.02)
Float Height = 22.4 +/- 1.0 (0.88 +/- 0.04)
Main Jet = #115
Main Air Jet = 1.7
Jet Needle = 5D50
Needle Jet = X-5
Pilot Jet = #40
Bypass = 1.0, 0.8, 0.8
Pilot Outlet = 0.7
Valve Seat = 2.0
Starter Jet = #32.5
Pilot Screw = Preset
Throttle cable play = 0.5-1.0 (0.02-0.04)

Ok, now you know what carbs I have. I got the 1980 GS550E 3 days ago from a friend that has had it for 2 years and has tried to get the stock carbs to work. When I got the bike the carbs were leaking fuel and no fuel was getting to the engine.

I completely clean the cabs. I have soaked every part in Chem Dip and reassembled. I put on new O-rings and gaskets. I also made sure the manifold O-rings are ing good shape. The bike now starts and runs but it idels around 4-5 thousand RPM. I am not sure that I set the pilot jet correctly(The pilot jet that is in the float bowl compartment) . I just bottomed them out and then put the plug back in...Is that correct? I have the Air Screw (the one on top of the carb) set 1.6 turns out. The idle screw is backed almost all the way out.

Please help. I have tried searchinf the thread but could not find the info. I am pretty sure that I am getting to much fuel I just dont know how to fix it.

Also I do know that the throttle linkage is not to tight, that part is fine. One more question, is the air jet that is on the airbox side of each carb need to be bottomed out or does it need to be backed off as well?

Thanks

 

[JEEPRUSTY]

To start these are the specs for my carbs..

1980 GS850GT Carburetor Specs
Unit of Measurement = mm(in.)

Carburetor type = Mikuni BS32SS
Bore Size = 32 (1.26)
I.D. No. = 45110
Idle rpm = 1050 +/- 100rpm
Fuel Level = 5.0 +/- 0.5 (0.20 +/- 0.02)
Float Height = 22.4 +/- 1.0 (0.88 +/- 0.04)
Main Jet = #115
Main Air Jet = 1.7
Jet Needle = 5D50
Needle Jet = X-5
Pilot Jet = #40
Bypass = 1.0, 0.8, 0.8
Pilot Outlet = 0.7
Valve Seat = 2.0
Starter Jet = #32.5
Pilot Screw = Preset
Throttle cable play = 0.5-1.0 (0.02-0.04)

Ok, now you know what carbs I have. I got the 1980 GS550E 3 days ago from a friend that has had it for 2 years and has tried to get the stock carbs to work. When I got the bike the carbs were leaking fuel and no fuel was getting to the engine.

I completely clean the cabs. I have soaked every part in Chem Dip and reassembled. I put on new O-rings and gaskets. I also made sure the manifold O-rings are ing good shape. The bike now starts and runs but it idels around 4-5 thousand RPM. I am not sure that I set the pilot jet correctly(The pilot jet that is in the float bowl compartment) . I just bottomed them out and then put the plug back in...Is that correct? I have the Air Screw (the one on top of the carb) set 1.6 turns out. The idle screw is backed almost all the way out.

Please help. I have tried searchinf the thread but could not find the info. I am pretty sure that I am getting to much fuel I just dont know how to fix it.

Also I do know that the throttle linkage is not to tight, that part is fine. One more question, is the air jet that is on the airbox side of each carb need to be bottomed out or does it need to be backed off as well?

Thanks

check your throttle cable it may be maladjusted or caught up in the twist grip housing

 

[Nessism]

check your throttle cable it may be maladjusted or caught up in the twist grip housing

Yes, this. Also set your pilot screws to 2.5 turns.

 

[DanTheMan]

Also, check your intake boots for sealing. If they're leaking (airbox boots as well), this will cause an uncontrollable high idle. Did you replace the o-rings on them (intake side only)?

 

[tsabadlk]

check your throttle cable it may be maladjusted or caught up in the twist grip housing

Throttle cable it good.

 

[tsabadlk]

Yes, this. Also set your pilot screws to 2.5 turns.

you are talking about the pilot screw in the float bowl that has the rubber plug on top of it right?

 

[tsabadlk]

Also, check your intake boots for sealing. If they're leaking (airbox boots as well), this will cause an uncontrollable high idle. Did you replace the o-rings on them (intake side only)?

I did pull the intake boots and looked over them very well. There are no pin holes at all. I look at the O-ring and they are in great shape.

 

[tsabadlk]

Thanks for the info guys! keep it coming. I have the carbs pulled now and have the float bowls off. I think I need to turn the pilot screws in the float bowl (the one that has the rubber plug on top of it) 2.5 turns out correct?

Also does the Air Jet on the air box side of each carb need to be back out so far or set all the way in?

 

[tsabadlk]

Ok, it's probably just me but I'm a little confused. You posted the specs for an 80 850GT but say your bike is an 80 550E. As for the 'pilot screw' you have it right, under the rubber plug.

Ya sorry the carb specs are correct though

 

[tsabadlk]

Does the main jet need to be back out at all also? What about the Air Jet?

 

[Nessism]

The pilot jets are in the carbs, under the rubber plug. These jets need to be fully tightened (snug). The pilot (air) screws are on top of the carbs, in the front. Those are adjustable screws that need to be set to roughly 2.5 turns from lightly seated.

Regarding the intake boot O-rings, if you didn't replace them they are sure to leak - causing a high idle.

 

[cowboyup3371]

The pilot jets are in the carbs, under the rubber plug. These jets need to be fully tightened (snug). The pilot screws are on top of the carbs, in the front. Those are adjustable screws that need to be set to roughly 2.5 turns from lightly seated.

Regarding the intake boot O-rings, if you didn't replace them they are sure to leak - causing a high idle.

Thanks for clearing that up Nessism as I was almost confused since I remembered being told to seat the jets.

 

[850 Combat]

Some of the 850's and 1000's have two places to hook up the throttle cable in the twist grip. One of them will not allow the throttle to return all the way. I recently made this error when assembling it without good lighting. It idled at about 5000 RPM.

I don't think air leaks are going to cause this amount of fast idle, and still beleive that there is likely a throttle return issue.

I was looking into a starter switch problem, which turned out to be a caused by kill switch wire pinched in the fork stop, which severed the conductors.

 

[Guest]

Ya thanks for clearing that up Ed. Helps when you get the right information.

 

[MisterCinders]

Did you bench synch the throttles when reassembling? If they are badly adjusted, they might remain open without any pressure from the idle screw.

Also the throttle line might seem fine, but if it jumped the track it will not allow the slides to close. IIRC that is what happened to 850 Combat. There was a picture in this forum of the stray cable. If I can find that thread, I'll link it for you.

 

[Steve]

I am not sure that I set the pilot jet correctly(The pilot jet that is in the float bowl compartment) . I just bottomed them out and then put the plug back in...Is that correct? I have the Air Screw (the one on top of the carb) set 1.6 turns out. The idle screw is backed almost all the way out.
...
One more question, is the air jet that is on the airbox side of each carb need to be bottomed out or does it need to be backed off as well?

All the jets inside the float bowls should be snugged down. The pilot air jet in the carb intake throat should be snugged down. The ONLY part that is adjustable is the "idle mixture adjustment screw", which is the one you are simply calling "air screw". Most of us use a preliminary setting of 2.5 to 3 full turns out from lightly seated, then, when the engine is warmed up, slowly turn them in until the engine either hits highest idle speed or starts dropping speed. If it never increases, but starts dropping, just turn it out about 1/4 turn from where it starts to drop.

Your high idle speed could be from a linkage that is stuck somewhere, or your idle screw might still not be out far enough.

One more thing that can induce a high idle is greatly mis-matched carb sync. If one carb is open a LOT more than the others, it will prevent a low, proper idle speed. Have you checked your carb sync?

NOTE: before doing a carb sync, you should really check your valve adjustment. If you sync your carbs first, then find that you have to adjust your valves, you will have to re-sync your carbs.

.

 

[Big T]

Thanks for the info guys! keep it coming. I have the carbs pulled now and have the float bowls off. I think I need to turn the pilot screws in the float bowl (the one that has the rubber plug on top of it) 2.5 turns out correct?

Also does the Air Jet on the air box side of each carb need to be back out so far or set all the way in?

No, the pilot screw is on top of the carb, at the front, covered by a cap

The one in the bowl needs to be seated. The air jet needs to be seated

The O ring on the pilot screw needs to be replaced

The air box needs to be sealed

Your high idle problem is common and results from air leaks. The intake manifolds themselves may have cracked due to age when you pulled the carbs.

 

[tsabadlk]

I figured out the issue. This is my first bike and I normaly work on 4 wheeled vehicals. The problem was that I did not have the air filter and snorkel on! Man I wish I would have thought about that before pulling the carbs again. Thanks a lot guy for your help.