I just picked up a minty 94 and its got a small bothersome problem. The idle likes to hang at around 2500 rpms for about 5 seconds before it comes down to normal. I pulled the carbs and they were fine, more than fine actually they looked brand new. The intake boots were fine and so was the airbox and plugs. The bike is totally stock as far as i can tell except for a junky V&H can that im probably gonna toss for the stock one but i dont think that can mess up the idle.
Im thinking it might be the pilot screws but i didnt touch them and i assume no one else has. Anyone got anything else to check?

 

Dirty throttle cables could be dragging, causing a little hang. routing of the cables can make a difference too.

Also do you have any free play in the throttle? There should be about .25" that you can rotate the grip before you feel the throttle take up the slack. If not, djust a little free play into it and see if that helps.

 

air leak

 

I checked the throttle free play and it was fine. I even went so far as to take it all out and put it back again with no change in the hanging rpms.

I think its an air leak too but i went over everything. The intake boots are fine and so are the carbs. Is there something im missing that i dont know about?
Off the carbs i have 3 vent hoses. The center big one goes to a box on theback of the airbox and the 2 smaller ones are just open to the atmosphere. I also have a bigger hose going to the back of the airbox too from the motor. They all look normal though.

 

take carb cleaner and turn the bike on and let her idle. Spray the engine where the gaskets are (i.e. Head gasket, valve gasket) and see what happens. Nothing, no air leak, it goes up then you gots an air leak

 

I tried the carb cleaner this morning with no change in idle. I did however take it out and beat it unmercifully on the highway. It seems to have gotten alot better. It only hangs for a second now at 2k then drops. I dont think this bike was ever really ridden so it just need to stretch its legs before it settles into my riding style and cleans itself up.
Im still gonna keep looking for a fix to the hanging rpms. I may try to reseal the airbox.

 

Any chance the butterfly valves aren't closing properly when you release the throttle? Maybe sticking a little bit or a weak return spring?

 

They checked out ok. The return spring is really strong on it to. Putting the cables was a chore.