exhaust question

[bill acamo]

just picked up new 4 into 2 exhaust but have chance to get 4 into 1 from
a guy i work with is it worth the rejet and cost for the added performance


Thanks Bill
bil366

[tfb]

Bill,

What model of machine are we talking about here?

If changing the exhaust system is the only mod. your engine has (eg. it's not rebored, or lumpy cams, ported, etc.) then you probably won't need to rejet. You might need to richen the pilot screws on the carbs, though.

What do others on the forum reckon?

Mike.

[Anonymous]

I reckon that if you don't need to rejet after installing a 4 in 1, the pipe isn't breathing any better than the old pipe. KInd of aggrivating, that rejeting, but worth the effort.

[bill acamo]

thanks guys have a good night

[KEITH KRAUSE]

If it's a quality 4-1 pipe, you generally need to go up a full size (5) or two on the mains. An additional 1/2 turn out on your mixture screws helps the pilot circuit. The needle shouldn't need raising.