James Gemmill wrote:
This might be a good tip, I'll checd with local mechanics at Lake
Powell next time I'm there.

If they are familiar with your boat/engine combination they should be
able to tell you if you are getting anywhere close to the performance
expected or possible under the conditions existing at the lake.

It sounds like the mechanic you mentioned my have just been stating the
published figures based on sea level performance. At high elevations and
temperatures your engine simply will not produce as much power as it
will at sea level conditions and may be effectively "overpropped."

There is a combination of prop size and rpm (maybe higher than 4600)
that will allow the engine to produce as much power as possible at the
lake but the boat will still not perform as well as the best prop/rpm
combination at sea level.

Good luck.

Rick