well 3.5 are too small for any real fun, and what size tires are you running?
edit- ahha i didn't realize this was a 3 hp engine yea, 4:1 is a little ambitious for a little engine.
go to daremotorsports.com the guys will reply to email occasionally but he should answer the phone. he has the most comprehensive build up packages for the tec engines, otherwise just replace the carb, as the engines aren't really built for governor removal. unless you go and get the full...
take an open ended wrench and use the closed side, then hit the wrench with a hammer. unless you have air tools. eventually it will break the bolt free.
http://www.reliablegokarts.com/transmission.htm
yes it is a live axle and i got the motor apart today... no billet inside =(. oh well any who i was wondering about the governor set up on this motor. the throttle is connected to the butterfly on the carb but the governor is still there. can i just replace the connecting rod and pull the gov...
well after long test run yesterday my kart has improved 10x but it still cuts out here and there so i am still messing w/ my gov spring. as for your situation six have you tried returning your carb to stock? maybe the honing messed something up? have you tried cleaning your in tank fuel screen?