Hey everyone, first post here. So I'm in need of some serious expert advice. I have a 1993 Polaris 350l 2x4 that will crank but not start and after cranking for to long it back fires.
To start at the beggining, I tore this atv completely apart and replaced everything that was bad. All bearings were replaced, all new seals, had to replace drive gear and counterbalance as the thread for cooling fan was gone along with pitted real bad with rust. Wasn't getting spark, found out stator was bad, had no ohm reading. So I ordered a used one off ebay, that one has an ohm reading of 120 and now i get spark. The piston looks like its in decent condition, visible tics on one side but cant feel a groove the rings looked ok as well. The counterbalance and drive gear are on their timing marks. Seemed like that was the only thing that had to be lined up since the rest lines in with the woodruff keys. And now my dilemma seems to be bad compression. I've taken this engine apart twice now. The 2nd time I found I only had 30psi compression. So I did the leak down check found a seal leaking in stator side changed it out. I have now installed the engine again and once again I still only have 30psi compression. When cranking it seems to have a decent push out the exhaust so im not sure if im doing the compression check wrong or it is an issue. This is my first rebuild and I'm just about at a total loss with what the issue is. About the only thing left is getting a new piston kit. Any advice or other related experience would be greatly appreciated.

Updated, I now have 60psi of compression. Cylander jug was leaking.