Polaris 250 Trail Blazer
#1
Polaris 250 Trail Blazer
My son has a 2000 250 Trail Blazer. It has a problem that it constantly fouls plugs. It also is backfiring through the exhaust. It backfires so violently that it blows the exhaust off at the jug and past the next joint. I just had the jug bored out .5mm and a new piston and rings put in. I need some help. Could it be that the main jet needs to be one or two sizes leaner?
#2
#3
Polaris 250 Trail Blazer
Thanks for the reply. I think I found the problem today. The pilot jet had worn grooves into the seat. I replaced them both. No more backfiring. Now I notice that it seems like the motor doesn't top out correctly. When I'm hill climbing the motor stays at relatively low RPM's even though I have the throttle pegged. Any ideas?
#4
#5
Polaris 250 Trail Blazer
The slide is coming the whole way open. I spent a couple hours trying different air mixture screw settings. The best setting seems to be one turn out, but I'm still having problems with it bogging when I dump it to full throttle. I tried moving the needle jet clip up and down with no drastic change. I still have the additional problem of the ATV not reaching top end on hills. It will top out on the level, but not while hillclimbing. Should I try a smaller pilot jet and a bigger main jet? Any other suggestions?
#7
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#9
Polaris 250 Trail Blazer
I bumped up the main jet two sizes today and the ATV is running much better. I think the backfiring was occuring when th engine wasn't properly warmed up. After I put in the new main jet I took it for a ride up our hill. It went right up at full throttle with no hesitation. I'll keep my fingers crossed. Thanks for all the ideas folks. I'll keep everyone up to date.
#10