Torque Monster

[660 SilverTip]

I can't wait until my engine loosens up because I know the power will increase. I mean it has quite a bit now and I have not done any engine mods yet. I have almost flipped it over a few times with a rip on the throttle. The thing pulls heavy loads with ease. Hey? Can anyone tell me if that exhaust end cap mod works or not?

 

[MrSled]

I have spoke with Kevin at Port Washington Yamaha and he said jetting up and changing the needles is req'd to get the most out of the mod. I will try and get more details.

 

[660 SilverTip]

Have you come up with anything yet?

 

[MrSled]

I was hoping Kevin would see this and give us some insight...guess I will have to get a hold of him.

 

[Port-Parts]

If you remove the end cap and go into the rear of the exhaust there is a plate on the bottom half of the muffler. Guys are drilling 8-10 holes in this plate from the rear to provide a more straight thru exhaust flow. They also modify the end cap outlet to provide more flow. Some have removed the outlet tube completely others have removed it and added a new bigger diameter outlet. Some have done this and left the jetting stock others have went up a size or two on the main. All have reported an increase in performance and claim the machine wheelies much easier. I have only rode a Grizz with 28" tires that had this mod and it definitely seems to accelerate better with this mod.