Need a little help on this fellas. I thought that I was running rich due to: 1. At WOT, RPMs slowly climb to peak (maybe they're just climbing because I'm easing back into the superman position) 2. Black Plugs 3. Engine bogs and sputters on take off (except the first couple of hours with a new set of plugs and no extended idle times).

I took my head off for the first time and the tops of my pistons are black, almost completely covered in carbon, except for a few small clean chips around the outside of the piston, which I thought meant that I'm running very lean.

I installed the 1100 waterbox last night, but am afraid to run it due to it is supposed to cause slightly higher pistons temps. If I'm "on the edge", this is bad. If I'm rich, then it's good.

Let me add a little more...I ran regular TCWIII oil (lubramatic) in it last year, but have switched to amsoil. Maybe the crappy oil caused the engine to carbon up?? Ski is a '98 GP1200.

Any suggestions??

Dave

Sounds like you are running pretty rich.
One way to find out for sure. Lean the high speed screws about 1/4 turn and see if you pick up more RPM. If you do then keep going leaner until the max RPM's start dropping off then go 1/8-1/4 turn richer or wherever you feel comfortable running. You should do several runs with each setting to verify the result. Hopefully you have a good tach. A tiny tach will work but a PET is better. Dont try to use the stock tach.

***THIS KIND OF TESTING CAN ONLY BE DONE ACCURATLY ON VERY SMOOTH WATER.***

Also dont put too much stock in what RPM others tell you that you ski should be turning. LOCATION is very important, elevation and barometric pressure will have a dramatic effect on peak RPM's. My GPR can only turn 7050 at the lakes near my house but I can turn over 7280 in the north west portion of the state.