There is three basic mods I want to do to my YZ: Full exhuast, Accerator pump, and Big bore kit. Wanting to know which parts work best together. I like the fmf 4.1 but am not sure on the other parts brands other than I dont want Athena. What are you all running or building for others?

Why not the Athena???? I've got one on a RMZ that has over 170 hours with a expert rider. Keep water and oil in it and it works great!!!! Nothing wrong with the FMF exhaust. Works good. We never did the acc. pump thing... After the 290 kit was in a while I did stage 2 cams that helped...

I've used Cometic, Vesrah, and Athena. I think the Athena gaskets are the highest quality of the three.

I got a 2008 with athena 290 fmf 4.1 and hot cams stage 2. Bought it with mods. Great combo, runs strong, never had an overheating issue, starts easy. Combo has 75hrs on it.