My Gosh GS650 Woes! Engine revs to 9k after starting..

[earlfor]

Re: 650

The slides should be in the full down position when you look. You will need to push them up with your fingertip and hold them up to be able to see the throttle plate on the other side. I doubt you will be able to accurately see the required 1/32" or less throttle plate gap without removing the carbs. Besides that, you need to have all throttle plates set to the same minimal gap at rest. I would just pull the rack, set all the throttle plate positions and work the throttle linkage with my finger while observing throttle plate operation and return. Its is a fact that the rpm cannot increase if the throttle plates are closed at idle and return to the closed position after being opened. There is something mechanically wrong...gotta find it.

Earl

Ok, When i put them together it was not an issue but who knows now. I am going to have a look inside with a mirror through the airbox to see what the slides are doing and if they are up maybe i can see the throttle plates too..

Thanks for all your suggestions.

Richard

[Anonymous]

carbs

Ok I have the carbs on the bench.. I don't see any space between the plates and the carb body. I have a small wire i mic'd at about 1/64" and it does not go in anywhere. I however did notice on carb #1 and #3 the bores are not perfectly smooth where the throttle valve closes.. perhaps this can be my problem?

slides are all the way down..

[earlfor]

Re: carbs

I dont think a slight roughness in the bore of two carbs would be the cause.
The part I cannot get past is that if the throttle cable is disconnected, then the springs on the carb linkages hold the throttle plates in the closed position.
Engine intake vacuum at startup would not be strong enough to suck the throttle plates open against the heavy spring tension of the carb linkage.

Do you have a manual for the bike and do you have the float bowl heights set to what the book specifies?

Do you have a 5/16" fuel line between the petcock and the carb fuel Tee?

If you have any kind of inline fuel filter between the petcock and the carbs, git rid of it.

How many turns out do you have your mixture screws set at?

Do you know what size main jets are in the bike?

When you put the carbs back on the bike, make sure you have all the rubber boots sealed on both sides of the carbs. Leave the throttle cable unconnected. When you start the bike, reach between the carbs and hold the linkage between the 2 and 3 carbs in the closed position. This will insure that the throttle plates are not opening. If rpm increases as it always has, then we at least know it is not the throttle part of the carbs that is the problem. Let me know what happens.

You havent installed an aftermarket 4 into 1 or pods??? right? stock?

Earl

I however did notice on carb #1 and #3 the bores are not perfectly smooth where the throttle valve closes.. perhaps this can be my problem?

slides are all the way down..

[JJ]

When I changed the handlebars on my '83 GS1100G, I inadvertently put the throttle cable into the wrong hole in the twist-grip assembly. There are two holes, and I chose the wrong one. When the engine started, the RPM's skyrocketed instantly. I changed hole locations in the throttle assembly, and all was well. It may not be your problem, but it's worth a look-see. Good luck!

[Anonymous]

I wish that was my problem I picked up another set of carbs off ebay for $10 and i am soaking them right now in carb-dip. Hopefully this will resolve my problem or at least eliminate carbs as my problem..

[KEITH KRAUSE]

I have'nt read this whole thread, but the problem has to be either a very poor carb synch or the diaphragm assy' is installed wrong. It only takes one carb to cause this. I would check the seating of the diaphragms/springs and then, if needed, do a manual synch by the book.

[Anonymous]

SUCCESS!!

Finally some success. I took my $10 ebay carbs and rebuilt them and now my bike is running sweet! Now for the safety inspection..

Thanks all for suggestions..

[Anonymous]

Just out of curiosity, when you push the slide up and release it, does it go back down fast or is it damped? This will tell you if the diaphram is intact.

Strange problem to say the least. I would have thought that there was no way for the idle to increase if the throttle plates were down.

[Anonymous]

yeah not sure what the problem was.. i just got a set of carbs off ebay and rebuilt them and now all is well...