i have a 2005 yfz 450 with a duncan fatboy 4 on it, i love the fatboy but it is extremely loud, i dont know if i should just get a turn down and spark arrestor screen for it, how much will it quite it down it says 2-3 dbs, is that alot and does it require rejetting? but the other exhaust i am lookin at is a fmf q4 with a megabomb head pipe, if i can quite the duncan down for cheap ill stay with that but is the q4 and megabomb better performance?

 

Hey Jo, the fmf is less noise, I have fmf Q series, I took it off and installed Yosi on my 660, fmf is quitier but yosi puts out more power for my, I have full system and might be willing to sell for around 200 bucks if interested, yosi is too loud for ya though

YFZ 450
ESR pipe and intake
cam mod
LTR 450
498 trinity kit
Yosi pipe@power commander
660 Raptor
Yosi pipe
12.5.1 JE pistion
Stage2 Hotcams
K&N filter
Rev box
05Banshee
2 much