So i got this 1989 yamaha pro hauler turf model the guy i got from sat in a garage for 12 year it is missing some parts it was missing stator with cover and missing a seat and one of the back plastics. So there is 0 parts for yamaha pro hauler i check ebay everywhere and no parts for pro hauler. So after doing some research i found a stator with cover from a 1987 yamaha moto4 225 moto4 was the closest same type engine like the pro hauler so i went ahead and bought it and the cover and stator from the yamaha moto4 fit perfect to the pro hauler. Now here the other problem its having spark but now i try to start it all it does it back firing timing looks correct i checked valves are good but why is it back firing?

 

Check your flywheel key hasn't broken, that could be why the cover was taken off in the first place.

 

And, have you drained out all of the old fuel....added new....and cleaned and rebuilt the carb...checked the air filter, as it's certainly "rotten" due to age.

 

Just keep on tweeking with carburetor. Should come out good. Make sure the fuel **** is in the on position.