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Doug E.
Doug E., Kawasaki Master Technician
Category: Motorcycle
Satisfied Customers: 2886
Experience:  Professional motorcycle mechanic since 1978. Vintage motorcycle restorer.
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I have an 92 polaris 350 liquid cooled trail boss idles..stalls..Carb

Customer Question

I have an 92 polaris 350 liquid cooled trail boss idles decent but if when your going at a pretty good speed and then open it wide up it stalls big time. Carb is clean, aif filter is clean,
what are some things i should check?
                                      Thomas Harmon
Submitted: 7 years ago.
Category: Motorcycle
Expert:  Doug E. replied 7 years ago.
Hi Thomas,

When did this problem first start happening? Have you recently moved and changed altitudes?

If you can, please take a couple of high RPM passes, shut off the motor and take a spark plug reading. What does the plug look like?

Doug
Customer: replied 7 years ago.
no i just bought it and have already changed the plug its fine, its a variable transmition and the belt is ine on it runs great in low gear just in high when Im climbing or already going fast then oped it up.
Expert:  Doug E. replied 7 years ago.
I need to know the color of the plug when running at high speed so I know if you have a fuel problem.

Doug
Customer: replied 7 years ago.

on this model you have to take fuel tank almost off to change plug. its a two stroke

and idles fine even when reving it up at high rpms if it was fuel than i would think it would be smoking or missing when idling. could the fuel filter be what causes it at high speeds. when im going about 50 mph it feels like there is still plenty of throtle left then i push it in and it stalls much like a governer does on a vehical. the two stroke oil is injected internaly. it seems two be working fine

Expert:  Doug E. replied 7 years ago.
It sounds like a lean condition which is why I am interested in what the spark plug looks like. A lean condition in a 2-stroke can be an indication of several problems that can lead to engine failure.

You can also use an exhaust gas analyzer.

Doug
Customer: replied 7 years ago.

dont have one. heres something else i thought of the gas adjustment in the carb looked liked it was screwed in two tight and left an indention in the seat so when you turn it one way or another now thers no change in the idle. so i adjusted it on the electronic throttle.

but even still before i adjusted anything it still ran out the same polaris i have always heard are tricky. woulded have a qestion on my yamaha or hoda easily rebuilt them this one is different

 

Expert:  Doug E. replied 7 years ago.
It's possible they damaged the air screw, but that will have no effect on your high speed running. That only handles fine tuning the running at idle to 1/8 throttle. It should be about 2.5 turns out from seated.

I understand that it is a big bother to take a spark plug reading, but it's critical to know what is going on in your engine. If the plug is burning white, then it is lean. You could have a crankshaft seal leak, and intake manifold leak, or the jetting may just be off. Try going to one size bigger on the main jet and taking the needle out of the slide and moving the clip down one notch.

If the plug is burning grey, then you know it is overheating and engine failure will result. Try the jetting changes, but it's very probable that the engine is leaking air at the seal or somewhere else. You will need to air test the motor to find the problem if the jetting change doesn't fix it.

Let me know what you find.

Doug