Jetting

Brent1284

New Member
Feb 11, 2023
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I have a 1998 yamaha blaster I just bought, not my first blaster but my other one is stock. I just bored out top end to next size because this one had piston slap. Has kn air filter, air filter box lid is drilled, put boyson pro series reeds on it, deleted the tors and oiler. I did the engine break in procedure, that’s complete. My question is how to tell what jet I need in the carb? It’s the stock jet but when I tested it the spark plug does not have a tan ring on it like my other blaster gets which tells me it’s running lean. When I mix my fuel I use 32:1 mix, and I use Yamalube 2 cycle. I wasn’t sure if there is a exact size that people use or if they just guess and see if it works?