Chainsaw Repair

OK'  so it turns out the muffler filter was plugged solid. The equivalent to a clogged tail pipe. I didn't even realize they had one till I stumbled across it. Still a bit baffled why it would run great upside down but it makes perfect sense as to why it bogged down with no power.

Either way' problem solved. Thanks for the tips. They got me digging in till I found the issue.

Clogged spark screen never crossed my mind being you said runs upside down.  Thanks for letting us know the update and problem was solved.