idle at 5,000rpm

bike wouldnt run so i sprayed some starter fluid in the carbs through the air box it started right up but is idling at 5,000 rpm its not the idle screw i already checked what else could it be?

 

Leaking intake boots?

 

just replaced them

 

Has the bike been sitting? or is this a new problem, before which it was running/idling well? If it has been sitting then the next logical place to look would be carbs. I am by no means an expert, and lucked out on my carbs, the PO had just rebuilt them.

From what I understand airleaks in a few different places can cause a high idle. If not the intake boots (carb to head, not carb to airbox) then maybe the shaft seals on the carbs?

I have seen a few threads talking about a high idle.

Bill posted a response to this thread:
http://www.xjbikes.com/Forums/viewtopic ... +idle.html

That person's problem seems to be a little different, but it may have a similar cause.

Here is part of Bill's reply:
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Check for air leaks around your manifolds and throttle seals. Wouldn't hurt to verify you float levels too. Check your enrichment circuit connection and make sure the plungers seat all the way when the choke is off. Sometimes you get the wire a bit tight and it says open some.
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You may also read up on the 'clunk test'.

 

its a new problem just started when i sprayed the starter fluid in it

 

Well the simple fact of the matter is that the engine can't stay running at that kind of RPM level without enough air, fuel, and spark. So I'd venture to say either your carb pistons are sticking up (read up on the clunk test for that) or you've got some kind of fairly major air leak somewhere else that's causing it.

Either that or if the carbs were just rebuilt, maybe they're way out of sync?

 

check that the throttle cable is not sticking, get to the carb end of the cable & push the lever down with a screwdriver, or the butterflys are catching, or as prev' post slides are not shutting down.

 

There MUST be something opening the Throttles or the Throttles are stuck open.
5,000 rpm's isn't Idle.
5,000 rpm's takes some Main Jet Fuel to achieve.

Some Gas and Air is getting in there to bring it to 5-Grand.
Look for something causing the Throttles to be held open.
Look for something allowing Fuel to pour in there, too.
Stuck Diaphragms Pistons
Open Enrichment
Air leaks
Fuel leaks; too.

 

He mentioned that the problem started after the bike wouldn't start and he used starter spray to get it to start.

If the slides were stuck open it would cause too much fuel to enter the chamber while trying to start, i.e. flooding it. So the problem predated the starting trouble, i.e. not related to using the spray.



Does it start w/o spray now?

 

no it wont start with out spray but it dosent take much of it.

 

Maybe pull the carbs and look at the throttle blades. They could be adjusted so that 1 2 & 4 are set too far open. Bench sync and reinstall and see what happens.