Im going to put on a new muffler this weekend. Do I need to rejet (dont know what it means just read somewhere that its required when changing exhausts)
Maybe, maybe not. If only an exhaust, you may get away with stock jetting. If doing an air cleaner along with this, then yes.
Many have not needed a rejet if only doing the exhaust. I'll let others chime in here.
I change exhausts and don't re-jet.
We have a 4 stroke engine. Intake and exhaust are separate. Stuff gos in one side. It burns. It exits the other side.
On the intake side, air filter+jetting+mixture are all related. Spark plugs also come into play. as well as timing.
On the exhaust side, it is just a matter of "open the valve and let that burnt crap get out of here as fast as possible because we got an intake to perform now".
IF we were still running 2 strokes - then YES - intake and exhaust are interconnected. They are pretty well isolated on a 4 stroke.
(I know Mister and Sledge will now rip me apart - go ahead and have your fun.)
All depends on your pipe. Cheap crappy ones probably, but a quality one then u might get away with it. More than likely in your Yankee bikes yes but on the Aussie and uk ones probably not
its a stock 2001 yamaha R1 muffler