ok heres my issue with this machine. i got it from lowes in crate. supposed to have it setup pdi from lowes. i started to have drive problems with it told to remove any oil build up from the flywheel kinda worked. keeped using it although had to do it again. got it ready to take to jd. but storm came in and i tried to fire her up. pull cord stuck second issue. started fine with electric start but not cord. so took her in. they ended up replacing the cam in it and fixing a bent flywheel. worked great when guy loaded it. got home and i started it up ok ran some snow and shut her off. keeped it in the run. so tried to fire her up again and now i get a big pop sound out i think muffler. then have to push 6 to 7 times before i get her to start. also notice at time a puff puff out of the muffler, also when she was running switched off it idil down and then just before it goes off it does this too puff puff, im thinking its relief valve? now could it be the cam not put in right. valves not set right? please help. i hope i did not get a lemon.
edit: when it tries to start up after the 6 or 7 it like starts very low rpm then kinda gradually ramps up to full