I've got a 2002 Xplorer 400 and I just rebuilt the top end with a bigger bore, piston and rings. Got it started and it sounds strong, but I must done something to the carburetor because right off start up the the idle rpms are at about half of what its got. :0 Ive messed with the idle adjuster and the throttle screw, but it really hasnt helped at all. any help?

-Caleb

 

The ONLY way an engine can RPM is with an air leak somewhere.
I can leak from a lot of places including the slide. If the cable is hanging up it will leak past the slide.
If the slide is put in wrong, it will leak past the slide.
If the carb boot is cracked it will suck air from there.

It's up to you to find the air bleed.

 

did you make sure when you put the carb back together thatthe slide was sealed all the way down in the carb?

 

I agree with the air leak, it can have an air leak just about anywhere. Could be the crank seal, head or base gasket , warped crank cases or a vac line that is bad or disconnected

 

Check the oil injection cable.They typically hang up either due to crud inside the housing or a frayed cable in.

 

hey thanks for the info. got it taken care of. the throttle valve wasnt down all the way...looks like the fix is complete, it runs really well...

Caleb

 

glad thats what it was as it's easy fix.