2000 Model Bass Tracker Outboard

The outboard is a 25 HP Mercury Marine. Whether I creep or give it full throttle at 3500 rpm the outboard sounds like the prop has left the water or it has shifted into neutral. Runs well otherwise. Couldn't find any postings with this problem

Re: 2000 Model Bass Tracker Outboard

are u trimming it out
sounds like motor is set too high

Re: 2000 Model Bass Tracker Outboard

It would help to know what boat we are discussing. Whether the engine is a short or long shaft, and where the AV plate is in relation to the bottom of the boat. You may also have a prop with a spun hub.

Re: 2000 Model Bass Tracker Outboard

I would guess this outboard is considered a short shaft and I have never heard of a AV plate. The trim is manual and I have not changed it all summer and motor has done well. The prop is not new but reworked I was told when I had to replace one last summer. What still puzzles me though it pushes the boat fine until you reach 3500 rpm every time. Spun hub would make sense

Re: 2000 Model Bass Tracker Outboard

To check for a spun hub, place a mark on the hub and another one on the blade part of the prop directly in line with the first mark. Run the engine until the problem occurs. Now check the marks. If they are still aligned, the prop is not the problem. If they are not in line the prop has a spun hub. The AV plate is the antiventilation plate. It's the flat plate directly above the prop. A short shaft measures 15 inches from the transom bracket to the AV plate. Long shaft is 20 inches. If the motor worked ok before and this is a new problem, I suspect its a prop issue. In other words, the prop can absorb power until it reaches 3500 rpm. At that point the slippage begins because the hub cannot hold the power any longer.