ninjette.org - View Single Post - New 250 owner. Idle hangs at 4,000 rpms. Carb issue?

jkv45 · August 31st, 2015, 09:14 AM

I would check that the slides rise and fall smoothly (engine off) by reaching from the airbox side and lifting them gently. They should feel smooth and drop without hesitation.

Also check for a vacuum leak around the intake boots between the carbs and the engine. What you described is typical of a vacuum leak.

You probably would do well to remove the carbs and go through them. Make sure to study up on it first and be sure to remove the caps on the idle mixture screws if they are in-place. You'll want to be able to make adjustments later, but 2.5 turns out is a good starting point.

Draining and cleaning the fuel tank is also a very good idea.

August 31st, 2015, 09:14 AM	#6
jkv45 Rev Limiter Name: Jay Location: WI Join Date: Jul 2013 Motorcycle(s): '06 SV650n, '00 Derbi GPR, '64 CA77 Dream 305, '70 CL450 Scrambler, numerous dirt bikes Posts: A lot. MOTM - Jun '18, Oct '16	I would check that the slides rise and fall smoothly (engine off) by reaching from the airbox side and lifting them gently. They should feel smooth and drop without hesitation. Also check for a vacuum leak around the intake boots between the carbs and the engine. What you described is typical of a vacuum leak. You probably would do well to remove the carbs and go through them. Make sure to study up on it first and be sure to remove the caps on the idle mixture screws if they are in-place. You'll want to be able to make adjustments later, but 2.5 turns out is a good starting point. Draining and cleaning the fuel tank is also a very good idea.