Low Revs

[Portland Billy]

Am experiencing low revs on port engine (KAD44) will not give more than 2500 under load. Stbd is fine.
Fairly sure it is not blocked filters but will change them when next on the boat.
Is it possibly just a recalibration control problem? New filters installed only five hours run in calm waters.

 

[CLB]

Numerous possible reasons. Filters are one, and don't rule out five hours being too little for them to be the problem. Other possibles include induction issues, turbo malfunction, loss of charge air, after cooler blockage or leak etc etc.

Finally, have you checked your props? A missing aft prop on the stbd engine will cause this problem. I have seen it twice. The stbd eng revs freely as it has little resistance, but the port can't, as its doing all the work.

 

[Momac]

As said engine that revs feely may be the one with the fault, because the other engine is doing more than its share of the work.
I had this when duo-props on one engine were a different pitch to the other (my fault for ordering what should have been fitted and not checking the props actually fitted ).

I guess damage to props on one engine may cause the same issue
.
or duoprop rubber hubs may fail/ slip

I also read about a boat where the duoprops had been fitted without the washers and that caused a similar fault.