Hi all,
I'm curious, my idle speed will not adjust below 1400 RPM. I can increase it by the screw but cannot lower. Can anyone shed any light on why this may be, vacuum leak? I've checked TB hoses and boots.

It also idles IMO very high for the automatic choke at around 3.5/4k until it heats up a touch then drops down gradually.

Thanks!

 

Yeah, 1400 is a bit high when warm and 3.5/4 is way high (mine will go as high as 2 when real cold.) You should be able to adjust to under 1000 rpm with no problem so it is likely a vacuum leak. I don't have any direct experience so can't be of much more help than that.

Definitely post up once you figure it out!

 

Does anyone recall a seal being between the throttle bodies and the airbox? Looking at drawings there appears to be a seal myn doesn't have...

But if there is a leak it would have to be below the TB (past the butterfly intakes.

 

Yes, there should be two gaskets there.

 

Those won't cause a high idle problem though, it pretty much has to be a vaccum leak.
The two hoses from under the throttle bodies that attach to the air cleaner box plugged in? Otherwise they are giant vaccum leaks.

 

^ There ya go!

 

Kinda comical looking at it! I did laugh at myself.
I rebuilt this bike last year after a collision, all okay just not the bike haha.
Took the aibox off, sprayed around the TB boots and the RPM sharply dropped off, almost stalling.
The lower clamps for the Intake boots are fully tight but its not sealing, I'm guessing this is a new boots and clamps situation.
cheerams.

** FIXED **

The inlet manifold rubbers had been abused and the little inner rim/lip had wasn't in good shape and the engine was sucking air in before the throttle bodies. Replaced rubbers and clamps as they were all gone.