1990 polaris 250cc 2x4 2cycle . need help with idle problem. after start up rpms go out of control (high) key switch wont shut off, kill switch wont stop it either. scary... have lots of ability on two cycle eng. but ..need routing of ..vac lines to carb.. throttle stop settings..air mix screw (turns out from full seat)would like manual on this machine if anyone has an old one. just got this thing and it has been setting for several years. removed and cleaned tanks ,carb.,new gas filter,oil replaced. vac lines to carb were laying under carb whei i found them . what a mess. helllllllp!!!!!!!!!

 

better check for an air leak somewhere. is the throttle cable sticking, is the slide going all the way down?

 

You can go to bikebandit.com and view exploded diagrams for your year/model atv, like carb, crankcase, etc.

 

The ONLY way an engine can RPM is it's sucking air.
Stendori hit on the big 3. Another is the crank seals.
I would guess the slide is not in correct if it goes that high.