fishingaggie
New member
I have a 1987 Mercury 25xd. It starts and runs great up to about half-throttle. Once you get to half throttle, the engine RPM's will rev and the the motor will stop moving the boat forward, similar to a spun hub. If you drop it back down to idle, it will run perfectly up to about half throttle. It is very repeatable and happens at exactly the same rpm's every time. It has been a real bugger to fix because it runs perfectly in a tank, all the way up to full throttle. It's only an issue under a higher load (when it's pushing the boat). Any ideas would be appreciated!