Unable To Reach Maximum Revs

[beejay190]

Took the Bav out last week, nice calm sea so I decided to push hammers as far forward as they would go. Engines are D3 160 which the book says will make 4,000 revs. Port engine maxed at 3,500 ; starboard 3,700. Both props are clean and as recommended.

Any suggestions please as to why the engines are so far off max. Fuel filters, throttle cables, dirty injectors / turbos ? Should I put some injector / turbo cleaner in the tank.?

 

[AdeOlly]

Dirty bum would be my bet. The boat that is.

 

[aquatom]

It could be the variable geometry part of the turbo on the port engine has seized. It can happen if they are not thrashed enough. Any alarms / codes?

 

[rafiki_]

If she hasnt had hull cleaned recently, then look there first.

 

[beejay190]

Thanks Guys.

Aquatom : No alarm codes. I will however raise the issue with the engineer at next service.

Rafiki : Hull was cleaned 17 July. I have made a note to WOT it immediately after the next pressure wash

 

[rafiki_]

Thanks Guys.

Aquatom : No alarm codes. I will however raise the issue with the engineer at next service.

Rafiki : Hull was cleaned 17 July. I have made a note to WOT it immediately after the next pressure wash

With the warmer water this summer, I believe that growth rate is faster this year.

 

[Gemini]

Very good chance its a dirty bottom, doesnt take a lot to affect the performance and lose RPM, and providing air and fuel filters are clean , Next time out and with warm engines, simple test, try each engine from standing start and slowly increase to WOT and note acheived RPM, then try the other engine, if both are pulling the same RPM+/- (You won't get 4000RPM more like 2800 -3000RPM ish ) its not mechainical, back to dirty bottom.

 

[beejay190]

Very good chance its a dirty bottom, doesnt take a lot to affect the performance and lose RPM, and providing air and fuel filters are clean , Next time out and with warm engines, simple test, try each engine from standing start and slowly increase to WOT and note acheived RPM, then try the other engine, if both are pulling the same RPM+/- (You won't get 4000RPM more like 2800 -3000RPM ish ) its not mechainical, back to dirty bottom.

Thanks, I will give it a try.
Sounds exciting max revs on one engine. I wonder whether I will get on the plane and whether the boat mighty tend to wander.

 

[Tender_aft]

Dirty bum would be my bet. The boat that is.

This is where you can put me out of my ignorance. Surely if the bottom was dirty the engines would work harder to push it along so the revs would go to max sooner??

 

[rafiki_]

This is where you can put me out of my ignorance. Surely if the bottom was dirty the engines would work harder to push it along so the revs would go to max sooner??

Sorry, too much drag, so the props simply ill not pin up to max revs.

 

[Gemini]

I doubt if you get on the plane or even over the hump, may only make about 16 Knots, boat will track slightly of centre depending if on Port or Starboard engine

 

[Tender_aft]

Thanks...didn't think about the props