Can't control throttle/RPM ,Redlines???

[eohvac]

Uh Oh,Carb trouble.I just cleaned my carbs,got airbox on(bike would not start w/out).Now,it starts up.but goes directly to redline.I hafta use kill switch to stop it(or Key).The throttle cable is not hung up.it returns to "normal position,on bars and at carbs .All diaphragms were in really good shape at cleaning.Slides also operated smoothly.I've done CV carbs before.Does this sound like a torn diaphragm?I mean ,Now it fires right up ,but I cant control anything and hafta shut it down before it over revs and blows up.Is a slide stuck?.I just had to walk away from it,so I'll have to appoach inside airbox with an inspection mirror.I just pulled the carbs again,and installed the stock airbox,So I guess it is back to the drawing board.But First,Any Idea on what it could Be?EoHvac PS this is an '82 GS650GL .Sat 9 years in barn.I knew carbs would need overhaul,&boy was i right.actually manufacture date is 11/81

 

[Big T]

Well, obvious things

Look in the carb throats and see if all the slides are down
Turn idle adjuster out until it doesn't contact
Lift each slide with a small screwdriver and see if it snaps back down
Check the choke action - on/off

I'm a bit confused - you started it 1st without an airbox? Then put the stock airbox on?

Did you do the complete disassembly and dip on the carbs?

The amount of revs you describe is way more than the typical air leak from bad intake boots or such

I think a torn diaphragm would make it rev slower, as that slide wouldn't lift

 

[Steve]

Actually, a lifted slide won't make it rev. The slides don't control the engine speed, the butterflies do.
In fact, if you were to lift all four slides and lock them into place, the bike should still start and idle nicely,
but will have a very hard time transitioning to anything higher than idle.

I would suspect that the idle control knob is turned in a couple of turns too much.
If it is turned enough to do a bench sync with a drill bit or other such object, it's open too far for a "normal" idle.

.

 

[BassCliff]

Greetings and Salutations!!

Greetings and Salutations!!

Hi Mr. eohvac,

Make sure there are no air leaks in your air intake system, sealed airbox, new O-rings on the intake boots, no leaks in the boots between the airbox and carbs, new weatherstripping on the airbox covers and on top of the air filter (if applicable), etc.

Here are some things to look at. Your 650 may be a little different, but you get the idea. New weatherstripping here on top of the air filter cage:

And for the side covers...

Air Intake Repair:
(Airbox removal, intake boots and O-ring replacement)​

Airbox Sealing
(by Mr. Roostabunny)

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BassCliff