What size mainjet for 89 blaster with few mods

Blastermit

Member
Mar 13, 2019
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i have a 1989 yamaha blaster thats bored .2 over with a weisco piston and boyeson power reeds stock headpipe aftermarket pipe dont know the brand sticker was burnt oil injection aftermarket airfilter no airbox lid i am currently running a 300 mainjet if i open it all the way up it will backfire and bog down no airleaks what size jet should i run thank you