Ive been thinking about upgrading my stock camshaft to a better one, or putting a new exhaust on my 400ex. Normally, I wouldn't rush it with a trip coming up, but I stripped the spark plug hole and had to take the engine apart anyway.

So, my question is: Should I go with a new cam or exhaust first? Would I have to do anything else like jetting it to get the most out of the cam? I have a White Brothers exhaust without a core which seems useless.

 

Any time you change the way that motor breathes you have to re-jet. It's a given that the motor is going to suck in as much air as it can, the jets are there to add the appropriate amount of fuel to that air to result in the correct air/fuel ratio. If you're bringing in more air than before, the jetting needs to be tuned to add more fuel to that air, or you run lean. And that can destroy a motor. Too much fuel produces a rich condition. It is better to be a little rich than too lean, but spot on is the goal. If you have a trip coming up soon it would be less of a hassle to put the quad together the way it was and enjoy your trip. When you get back and have time put a new cam and pipe on and jet it.

 

Sorry, double post.