Not Yamaha but its a 2 stroke lol

[hondaruss]

Hey guys havent been here in a while been to busy working on my new quad.. but i need some opinions

Here is the deal, its a 1997 Polaris Sportsman 350 2 stroke.. anyyyway i been pissing with this thing for a while and i am at a loss.. it dont start motor cranks over.. damn thing backfires out of the exhaust sooo hard it blows the exhaust pip off of the head thank god the springs are on it ..it wont run.. i have consistent spark, 150psi compression and good fuel.. just backfires hard reallllly hard.. anyone got any ideas? I am thinking about calling it quits on it and giving it away

 

[sicivicdude]

Check your flywheel key and if that's good, go ahead and drop it off at my house.

 

[royalt67]

LOL. I agree, it sounds like a timing issue. Check that key.

 

[fsuroxu]

Definitely the timing.

 

[yamerhammer00]

yep check the flywheel and the woodruff key, i was having some problems like yours, and civic nailed it as being my crank had high spots.