I have a 98 300EX and want to increase performance (speed) without losing torque for when i am in the mud. Thought about jet kit and changing sprockets. I have a aftermarket pipe on the quad. any suggestions of performance products.

 

a K&N air filter a after market rev box a edilbrock carberator and if you want to get in to the engine a hotcam came shaft good luck

 

Now lets think about this. Atv runs in mud. Mud dries everywhere and gets all dusty. Dust enters through K&N and destroys valve seats and wears rings. poop. I have a UNI and it makes me happy. If you dont believe me about the K&N, buy one, put a little clear grease (a.k.a. Vaseline) on the inside of your intake tract, then take it off after a ride and wipe it off. note the color of the paper towel. repeat with a UNI and note the results. Think with your brain and come to your own conclusions. Hotcams knows what theyre doing. If you really wanna haul, throw in a weisco 11:1 with that cam. IMO, without valvetrain work like 450rking said, rev boxes are not a good idea. (especially if you'll be winding it out in the mud.) I've heard alot of good stuff about elderbrock, but they're like 300 bucks. Just beef up your keihin with dynojet parts.

 

If you don't change the amount of air going into or out of the engine, why would a jet kit help anything??? (Unless you put on the aftermarket muffler without a rejet, then you are probably now running lean and hurting your engine????)

If you don't have an aftermarket header, get one. That stocker is pathetic! Plus, you can open up the airbox lid (EHS Racing lid), and UNI foam filter. And of course, a rejet.