won't idle, 4grand pegging

Alright. I have searched and done what I found to be relevant to try and remedy my problem. I have a 81 550 maxim. when I bought it , ran smooth, idled great. I replaced the intakes and still ran fine. The bike then sat for about 2 months while I was building a new rear fender, repairing the brakes etcetera. Well I then tried starting it and after the bike warmed up for like a minute the engine would rev to 4-6 grand. I tried the idle screw, no help, sprayed for vacuum leaks before it warmed up again and found leaking throttle shaft seals, so I replaced them, also replaced the idle mixture screws, I have them set at about 2 turns from bottom. I did clean the carbs, replaced the float needles, and any worn out o-rings on the carbs. I did a bench sync, double checked to make sure the throttle plates are not binding, which they aren't. Also the choke is off when this happens. I am at a loss, I know the throttle plates are no hung open and it is kind of hard to do a vacuum leak test when the engine is running at 4 grand, any help will be appreciated.

 

Looks like you have checked most everything. Some things I can think of. The throttle cable is to tight and keeping the throttle open a little.
The choke plunger seals are leaking and the choke is really not off.
The float level is to high.
Check throttle cable and recheck the intake for leaks and do a wet fuel level check.

 

At 4-grand ... the Throttles MUST BE Open and the Engine getting MAIN Jet Fuel.
NO questions about it.
There isn't any way Pilot Jets can feed enough gas to make 4Krpms.

Take a long screwdriver and press on the Linkages to see where they might be binding.
If you put New Manifolds on ... I'd look there.
I'd look for "Major Air" leaks at Clamps and Mating surfaces.

If you have NOT done so prior to reading this Post ... Scrub the Diaphragm Piston Bores with Medium ScotchBrite Pad.

You might have Diaphragms hanging-up.
READ: Clunk Test -- Link in my sig.

 

I did the clunk test and only had to scrub one bore, the throttle cable has slack in it, I will double check to make sure throttles are closing, but from inspection their is nothing binding them, guess I need to look at the intakes, anyone have any type of temporary seal technique so I can verify whether it is the intakes other than spraying propane or throttle body cleaner on them? hard to tell if they are leaking when the engine runs so high. Thanks for the input. let's hope I can get this figured out soon.

 

Well ...

You can use RTV and Tongue Depressor and Seal each Manifold to the Head like you were sealing a pane of glass into the window.

Make it impossible for AIR to sneak-in behind the Manifolds.

 

Thanks you all for your help, I do feel like an idiot though, the throttle plates were open just a little too bit causing the high rpm, I never thought the throttle stop screw was that sensitive, it idles good now and once I clean some caked on oil off the exhaust I will begin my tune and hopefully be riding this weekend.

 

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