My 1968 B&S 3.5 HP lawnmower engine (92902, pulsajet carb with two fuel
pickup tubes) will not start unless I remove the air filter; nor will it
start with just the air cleaner bolt installed without the air filter.
I have serviced the carb and replaced the gasket. I have checked and am
certain that the bolt is not interfering with the movement of the manual
choke.

Anyone experienced this problem?

Davy