top end power struggles. Please HELP me!

[tyler3]

I've just read a thread involving the exact same problem my 97 challenger 1800 is having. I've recently had my carbs rebuilt by a dealer with all nee seals put in. Everything was good for about 12 hours on the water. But now I'm having the same problem as others. Unfortunately the thread was closed before anyone seemed to get to the bottom of the problem. My boat starts fine both engines but at about 4500 rpm the right engine just stops putting out power. Left side right up to 7000+. It seems almost like the right engine is choking out. It doesn't die but just won't get up there in speed. I'm now stuck at about 35-40 mph. Could this be a clutch problem or perhaps oil rings or something else? If anyone knows this problem, some advice would be greatly appreciated.