Loss of Revs - Volvo KAD 42

[Reefencounter]

Hi all,

I still have the same problem, however, something strange on the last sea trials, suddenly engine revved to 3000rpm and i was doing 22knots, but it started to overheat. I pulled back the throttle and when the engine went back to normal temp I gave it full throttle again and only got 2500rpm max. Seems more and more like a fuel problem now? This is driving me crazy.

 

[alldodge]

Think I'm going back to an exhaust restriction, and it could be in the transom assembly leading to the leg. Can you get an borescope down the exhaust to the leg?

 

[Supercose]

Dear Reefcounter ,

As you know I had the same problem and same symptoms with yours.

My problem is solved.

I called a new mechanic from Istanbul and we had a sea trial.

My mechanic informed me that there are two main timing on KAD42's.

First main timing is fuel timing which is done on diesel pump and other is air timing which is done somewhere under kompressor brain.

And my mechanic informed me that there is a ratio between these two.

My boats air timing was under standard level and fuel timing was a little over standard thus made insufficient power.

So my mechanic made both two timing and ratio calibrations just in 10 minutes and then boat just cruised 3800 RPM with 33 knots.

Problem is solved.

May be you should check these two timings.

 

[alldodge]

Is there any manuals, bulletins or spec sheets listing how the air timing is done?

 

[K-2]

Air timing? Do they mean boost? Maybe a turbo waste gate adjustment?
Air timing is a new one to me.