Definitely don't mess with the governor without consulting a pro.

The engine should be able to reach "red line" in neutral, and it
shouldn't be hurt by pushing it right up to 2500 in neutral, as long
as its warmed up and has fresh oil, etc. If it will do this, there is
probably nothing wrong with it.

If it gets to hull speed at 2200, then that's all you're going to get
from it. Changing the prop might allow you to rev higher, but you're
already at over 85% of max, and that's what is often recommended for
small diesels, so my vote is for leaving it where it is.

I friend has just repowered with a Yanmar 3YM, and claims he was told
that he can run all day at 3600. I'm skeptical, however, and never
run my 3GM's at over 3200. I curious about other opinions on this.


Steve wrote:
In an earlier post I mentioned that I had changed props and the engine was
only reaching about 2200 rpm.

My (new) MD2B manual indicates this engine should produce 25 hp at 2500 rpm.

Yesterday while running the engine in neutral at the dock I noted that the
governor is limiting the engine rpm to 2200 rpm.

I hesitate to tamper with the governor settings and the OEM seal wires are
still in place.

I wonder if I should investigate this situation or be satisfied with the
2200 rpm since my boat reaches hull speed at this rpm.

Any comments or suggestions would be appreciated.

Steve
s/v Good Intentions