My blaster b1 kit from toomey came with a 310 main jet which sounded big but we puut in any way..the stock was a 230 and it fouls a plug after every ride so does anyone have any ideas for what jet we should use were gonna try a 300 and 290 next..we are at sea level..

 

I have the same kit except I have aktive reeds and billet reed spacer. Do you get the bogging down in the lower gears like I do? My plug looked pretty oily after a ride but am yet to foul one.

 

I recently bought a B-1 kit for my wife blaster and the 310 main was too rich at top end. I installed a 270 main and that hit the sweet spot, I may try a 290 main next to just experiment. Jetting a bike take patience and also what works for one bike at certian conditions will not work for another. The main jet only controls 3/4 - full throttle (top end), if your engine is not running smooth at top end you will need to adjust your main. If your engine is sputering at full throttle, you are running to rich on the main. I recomend to do a plug check, to properly do a plug check you must peg the throttle under a load (wind it out in 5th or 6th gear) (full throttle), then with it pegged, hit the kill switch to establish a top end (main jet) reading. Your spark plug should have a tannish to light brown color ( do not use a new plug for test, it will give you a false reading ). Good luck!