Try tapping the carburetor housing for a 5MM X 0.8MM thread. That's about .009" larger than a 10-32, and it should allow you to get a full thread in the housing without having to use Helicoils.

toolsadvisers.com/what-size-drill-for-m5x0-8-tap

Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!