Re: Gas boiling in carb
Plastic spacer or not. Fuel boiling isn't your problem. The float is not closing the float valve. Either there is trash in the needle and seat or the float adjustment is way off.
I suspect it is dirt in the needle valve. This is a common problem if you're not using an in-line fuel filter. The kit tanks are notorious for containing dirt, rust and scale that once gets to the carburetor will block the float valve from closing causing the symptoms you describe.
You need to drain then flush the fuel tank, clean the carb then install a filter between the tank and carburetor. That will probably solve your problem.
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