Clean the mainjet in the carb. It's not running out of air, it's
running
out of fuel. Serious.

CN
Thanks for the quick response.

Okay, I'll try that - but- it runs like a champ, even under full load,
with the top removed. That's why I think it's an air issue, when I put
the top down tight it dies...if it were the fuel, wouldn't it die even
with the top lid off?

JW