Kawasaki 750 Xi Supersport runs fine then won't rev
I have a 97 Xi Supersport, it runs for for 10-20 mins then the rev's drop and won't exceed 4000rpm on the tacho. The Overtemp light doesn't come on and the pisser is flowing. I've checked all the cooling which is fine. Rebuilt and jetted the carbs but still have the same issue. If you return to the beach, tip the ski on the side and rev it freely a couple of times it clears and runs again with no problem for 2-5 mins, the issue returns.
Questions, if the overtemp switch is failing will it light the overtemp lamp?
If the crank case has lost its seal would it cause a lean mix and the same issue, ie has the crank case drain seal failed. (The crank seals are new)
Any other suggestions or things to try?