Hi ANdy
Brown on spark plugs are a sign of too high of octane. When octane is correct and everything else is correct, plugs should have a light powdery gray color. Too much octane means that you are
still burning gas when the valves open up and you are not getting the correct effeciency from the fuel. There is a happy medium of when you have the correct octane for the compression you
have. It takes a while to get everything adjusted properly. You are probably a little too young and having too much fun to know all there is to know about how to obtain the correct
effeciency. Spend some time in the library and read about fuel effeciency. When I raced high-speed go karts, I bought an air density meter so I would know how to properly set my jets for the
race. It too some experimenting to figgure out how to use eerything properly but after a few times, I learned to look at the meter and know which jet to use. Full effeciency takes
preparation. A 9:1 motor should use 87 to 89 octane most effeciently. I am also a believer in water injection. Read up on that also. After using water injection, your pistons and valves and
all inside the combustion chamber will look like it was just steam cleaned when you take it apart. It also helps stop detonation. I got an adjustable needle valve and put inline to a vacuum
port on the carb. JC Whitney has a very good system that is controllable and is pretty much inexpensive and has good instructions on what it is all about. You can call them in Chicago and
they will send you a catalog. They have clutches, brake rotors and a lot of good parts that are cheaper than most places.
Mareo