i just put the fmf 4.1 titanium full exhuast on my 07 z400. then i rode it for a while and it bogged and died. then it didnt want to stay running. so i bought the fmf jet kit hoping it would help with the problem becuase i think i was running way to lean and burned out the plug.

would the bike start if the plug was burned and would it want to die if i hit the gas?

another question is the main jet is a 130 and the fmf kit says to put in a 130, is thats even gunna help at all with to even out the exhaust change? should i go a size or 2 bigger?

 

when i put a fmf exhaust on my banshee i had to rejet and adjust the neddle in my carbs... I also recynced my carbs at the time

 

i also have a k&n intake on my bike also to ensure I'm getting enough air into the motor