I agree witg Bob, that sounds like either decompression or ignition.
I would suggest removing the deconpressor, and blocking the hole with a spare spark plug (pop the hose over the plug bolt to seal the intake) then run it till dry, then, when you start it back up after refill, you will be able to see if tge issue is the decompressor, or ignition.
if the decompressor is the issue, either service it(clip type) or replace it(sealed type) otherwise, check the grounding of themodule, and do a 3mm gap spark test when hot, in a dark place, look for a nice, bright, strong blue spark, acompanied by an audiable snap.
