CD330 with M30 not exceeding 2000 RPMs

[Chris Reinke]

It is very rare that I push my M30 in my 330, but today I could have used an extra push while fighting an exceptionally strong current but I could not get anything more. My M30 was rebuilt about 5 years ago and runs great, but I found today I can not exceed 2,000 RPMs. I can continue to advance the throttle control, but the engine RPM's will rise to 2,000 and no further. In fact, once I advanced the throttle past the point where the tach reached 2000 the engine began to sputter a bit and the RPM's became variable (bounced between 1700 and 2000). So my first question is, do other M30 owners have the ability to surpass 2000 RPMs? I thought I recall reading somewhere that the engine is rated to 3000 RPMs. I do not get any carbon in the exhaust to possible indicate to much prop, as a matter of fact I think I am under propped (don't recall what prop is on the boat) because I am often passed by other similar size sailboats while under power.

[Steve Laume]

Fuel filters and clean prop would be the first, easiest and cheapest things to check, Steve.

[Chris Reinke]

Thanks Steve - I should have mentioned, the hull is clean and so is the prop. I can't get the RPMs above 2000 even when the trans is in neutral and no load on the engine. I did replace my fuel pump a few years back, but it was within spec for psi and don't think that is the concern.

[Sea Hunt Video]

Chris:

Maybe throttle linkage needs adjusting or repair or replacement

[David Morton]

Air filter?

[Oswego John]

Air filter?

That's what I was thinking. Something that would choke off adequate air needed for high RPMs.

Also check on what Robert suggested. Maybe a governor screw, etc. Something messed up in the throttle linkage.

Good luck,

O J

[Chris Reinke]

I have done more research and read over the M30 Owners Manual, Parts List, and Tech Manual. I now know the M30 has an overspeed governor which is a pretty complex assortment of springs and levers....now I am scared. I have read that it is a "centrifugal ball weight system" (means nothing to me) that has different components that are resoponsible for the at start control, at idle speed, at low speed, and at high speed. Plus another set of springs for high speed with overload, and stopping. I have read it over numerous times and still dont understand it, and still have no idea how to troubleshoot it. Any ideas?

[John Ring]

... I have read that it is a "centrifugal ball weight system" (means nothing to me) that has different components that are resoponsible for the at start control, at idle speed, at low speed, and at high speed. Plus another set of springs for high speed with overload, and stopping...

Sounds like a variant of the old flyball governor system.

Link: http://en.m.wikipedia.org/wiki/Centrifugal_governor

John Ring
CD36 Tiara