plug reading is an art run your quad with the choke on will cause a black plug the best way is to go to rich until it afects performance ie won't come on the main cleanly then go leaner but in the end it's still guess work and experamenting

 

I put on a 4 inch stainless Supertrapp, made for a car, it only weighs 3 1/2 pounds, compared to 9 pounds for the stock one. It sounds fantastic! It has a 2 1/4 inch inlet opening, so I made a 2 into 1 collector for it. It was only $100 on e-bay, so I took a chance on it, and I'm happy with it![img]i/expressions/face-icon-small-happy.gif[/img]

 

Ok... what you do to one side you must do to the other. I ended drilling 5x3/8" holes in the location I was talking about above and devised a filter out of the stock one and WOW she really came alive.
I wish I knew how to post pictures so I can show you guys....