I have a 2001 polaris trailblazer 250. I just recently put an exhaust kit on it, ran wonderful for about two weeks until it slowly started having starting problems. It turns over and is getting spark but doesn't start up. It will sometimes start when its cold. And if you get it running it runs great but seems to loose power as it gets warmer. Don't know if it has to do with compression. Any help would be appreciated!

 

Compression check is the way to know for sure. If it's 100 psi or less then time for a fresh top end. Hard starting or starts only when cold and runs for awhile then looses power sounds like it's compression related.

 

I have a 01 polaris trailblazer 250 it previously had trouble starting so i rebuilt the top end. And went to start it and nothing changed. It gets excellent spark the battery is good. It turns over but doesn't start up any help would be appreciated

 

May be more than just slapping a new top end on it. Plus if you just throw another piston or just replaced rings in without having it bored/honed for the correct over size piston needed like some have done,you haven't accomplished much if anything as far as compression. If the new top end has been done right,has good spark and fuel to the carb,the carb jets are clean and open,then see if it at least tries to crank with starting fluid. If it doesn't could be a crank seal problem. Usually the one behind the drive clutch. Plus not a bad idea to go ahead and remove the black wire from the reverse limiter module. It can retard spark if the module fails(all do sooner or later) and this can stop one from cranking also. Item#27.2001 Polaris TRAIL BLAZER (A01BA25CA) Electrical/Taillight | Cycle Parts Warehouse