The new style air filter boxes are dirt cheap on e-bay that
handle the newer style carbs, I sell them there as well.

But I would suggest you put the old coil back on, as the
newer coils are different from the old ones, and also, pull the muffler and look at the piston, tell us what you see.

Fish

Ordered the new air filter housing 1130 140 2800.
I was using the old box with the new carb design. DUH!
Hope this solves the problem.

Check (if it can be done) the fuel cap for a plugged up vent. Pretty hard to tell if it is so I have just replaced the cap a time or two in the past.

This doesn't happen often but when all else has been looked at...

Harry K