Chainsaw Repair

this is a new one for me  Im working on a new to me saw that was nearly starting and as I dig into it its actually backfiring and sending a puff backwards through the carb.

When I try and start the saw the mouth after the air filter gets soaked in fuel before backfiring.

I'm looking to figure out what would make a 2 stroke backfire?   How does on adjust or correct the timing of a 2 stroke saw?  I have spark and fuel but timing should be fixed shouldnt it?

THanks in advance

Brent

Started with the simple things

ignition sparkplug gas carb rebuild cab adjustment

Finally couldnt get the exhaust off to take a look in the cylinder and pulled the jug and found this.  Troubleshooting complete, Time for a new cylinder.

Now for figuring out if i sould use the more common 55mm cylinder and effectively make my saw into a 390 instead of 385xp? and what brand to source