Tony,
Thanks for your timely reply. I have read many of your articles and consider them “maritime gold” for the motorboat owner. I even managed to read the recommended one after my first post.
Quick history — Engine was torn down and inspected, measured and all internals found to be in spec,Ā valves reground,Ā turbo was just bolted back on (no leaks oil, ect, barely perceptible movement in bearings). This was all carried out around 4 years ago, (during overhaul of engine bearers in boat) and the engine may have 1000hrs since. Engine work was done as I had no history on it and I am in the trade. (Diesel Fitter). Boat originally had only 4″ wet exhaust, I replaced it with 5″ as recommended. Prop is a 3 blade 23×16 “mouse ear” style and the gear is a 1.5:1 zf220a. Best I can recall I was gettingĀ 2500 at around 18 – 19 kts. Cruising wasĀ 10 – 12 kts at 2000-2100.
“Lately” I guess means recently I have started commercially fishing for Coral Trout and so have increased the load on the boat (12 months now) and mostly cruise around 8-9 kts at 1600 but am noticing soot on the back getting a little worse than I remembered from before even at 1600.
I carriedĀ out a valve set a fortnight ago as part of normal maintenance, doing fuel filters, oil ect.
To put it on the mark, I guess I’m juggling between a boat loading issue OR engine power issue. The engine runs fine normally, sounds good mechanically (although a little noisy).
To unload the boat from the fish holding tanks and ice boxesĀ would be more bolts and work than it would be to replace the turbo (provided the QSB one will fit ) for testing purposes, so I thought if I had a figure I should see for boost, I could check it and sort out which area to address. I realise that I wont see full boost figures with low RPM’s but there should be a figure at which I’m getting enough air into the engine to run clean(er).
Also, I’m not after the last bit of performance, it just seems like its lacking a bit.
.
