Engine Problem MD22

[phuelin]

I have a 48 foot cat and am having a problem with port motor.
Motor will go into gear and rev when cold but when hot will go into gear but will not rev ?
Any suggestions ?

[skipperpete]

We need a bit more info to take a shot at this. What reduction gear? Saildrive? What propeller? Electronic or conventional cable controls.
It would be a waste of time taking multiple guesses without knowing more about the installation itself.

[skipperpete]

Originally Posted by phuelin

I have a 48 foot cat and am having a problem with port motor.

Motor will go into gear and rev when cold but when hot will go into gear but will not rev ?

Any suggestions ?

Is the MD 22 turbocharged? Any sign of engine overheat or unusual exhaust smoke. It would be worthwhile to operate the engine speed control lever manually at the injector pump to eliminate the possibility of problems between the bridge controls and injector pump

[phuelin]

Thanks for the questions
Sail drives are volvo ,props 15inch ,all controls are cable.
I have disconnected the cables and attempted to rev motor by hand but no revs .
I was told the problem is caused by something jamming the prop but have changed props to no avail.
I do not understand what the connection between the prop and the injector pump.

[skipperpete]

Thanks for the extra info. If the engine loses power due to a fault in the fuel system then lower or very low rpm under load is one result but if the rpm is normal when the engine is cold, the problem is much harder to explain. Is the engine able to reach high idle when the saildrive is in neutral, it should run up to fairly high rpm. Maybe the gearbox bearings on the saildrive are the problem, is the oil clean and level ok?