Something else has to be involved here. If you are certain you switched
from a 17 to a 14 pitch of the same size prop the rpm's would have to go up.
Even if the engine is old or worn. Are you completely positive about the
sizes of both props? That is enough of a pitch change that you should be
able to see the difference when looking at the props. No chance it has a
rev limiter on it?

"Jim and Becky" wrote in message
t...
200 rpm is so little I can't imagine spending the money on a new prop.
4000 rpm probably does not mean this will hold true for all like engines.
I had a bad cylinder in mine so you may want to do a compression check.


"Scott Downey" wrote in message
...
A worn engine would not develop full power. Dropping the pitch should
have
placed less load on the engine and reved it higher.


"Bruce Kingsley" wrote in message
...
Hi:

What would limit engine RPM? I have a 1976 SeaRay with a Merc 255
engine
that only produces 3800 rpm, the specs say it should produce 4000 rpm.
The
prop was a 17 deg pitch and we reduced it to 14 deg pitch but the rpm
didn't
change.

--


Regards;

Bruce Kingsley