I have a 1998 GP 1200 that we are having problems with. The engine is completley re built with new crank, seals, pistons/rings, and boring. The engine was leak tested as well. Problem is the ski idles perfectly in the test tank but will not rev up past 5000 RPM's. The carbs are all in check and completly rebuilt by Oside Bill. It seems like it is only running on 2 cylinders as soon as we gun it. Compression checks out fine in all 3 cylinders as well. We know the jetting is accurate as well. The engine has a mild port job and high compression head - everything else is stock. The ski ran perfectly before I seized the front cylinder. I had whole engine re built by a very reputable forum member.
I think the problem is ignition related at this point. The ski idles perfectly under a load in the tank but wont rev past 5k.

Has anyone ever experienced these symptoms? Any suggestions?