any prop calc boffins out there??

[DownWest]

Normally the throttle stop would have a seal put on by the injection engineer. You could reset it by a few threads and see if it alters the revs. Should do, but you might want a pro to look at it if this is the reason that it won´t rev. These settings are usually done on the test bench, hence the seal.
Andrew

 

[chrishelen]

Silly question,is your rev counter accurate?

 

[Peterduck]

If you're not getting the revs in neutral, is it possible that the engine is starving for air? If it's in a well-fitting engine box to keep the blighter quiet, this may be a possibility. Multiply the engine's capacity by the revs to get the number of litres of air used per minute. Divide this by 1000 to get the cubic metres of air; it will be impressive!
Peter.

 

[monkey_trousers]

don't know how accurate the rev counter but would guess reasonably so, its pretty new, and the engine doesn't sound like one doing 2500 rpm if that makes sense

as for its 'breathing', its sat in an engine room foot square 5 foot high, the inlet manifold has a breather pipe 6" in diameter leading out of the engine room through the deck to a vent box behind the wheelhouse, so its got plenty to suck on. I did try that possibility early on ad disconnected the inlet pipe from the manifold so it was sucking straight into the manifold from the volume of the engine room but made no difference. If it is governed I'm going nowhere near it! I want it serviced anyway so whoever is lucky enough o get that job(!) can advise hopefully