RE: [j4x-owners-group] Re: Can you provide additional feedback on your Max Prop?
- I too have experienced a lot of soot on the transom and I am sure it has nothing to do with the prop. I found fuel in Europe is much cleaner and thus little to no soot on transom. The minute I get a load of lesser grade refined fuel the smoke is back.
My experience covers over 8 years using European fuel and I am almost positive, poorer refining is the cause.
Here in the US, fuel is probably not much better than heating oil. I have also been using ValveTec additive with the blessing of Mack Boring and that ups the CTAN level which also helps to eliminate soot.
I have a Flexofold 2 blade prop which powers the boat fine at the proper RPM relative to redlining etc.
Bill Stellin Jaywalker Hull #6 1996
Date: Sun, 29 Mar 2009 01:01:18 +0000
Subject: [j4x-owners-group] Re: Can you provide additional feedback on your Max Prop?We have installed an 18" 3-blade Max Prop Classic on "Sandpiper." We tried pitching at 20 degrees (X=K, Y=E) the first year. We have the 3JH2TE. The engine redlines up on the governor easily. The next 2 years we set the pitch to 22 degrees (X=N, Y=D). The pitch matched our governor exactly, maybe 50 RPM over-pitched. Above 6.8 kts underway, the stern would squat, burying the exhaust. This made for an oily transom. I even put a new turbo on with only 850 hrs since new on the old one. I talked to PYI, J, and Yanmar, with photos, to no avail. Bill Boyesen of "Jimimy" set his back to 20 degrees to avoid smoke and we followed suit. So 22 is efficient for the engine but the boat wants to climb its bow wave. At 20 degrees, we stay below 7 kts and motor along at 2650 RPM, with about 30% of the smoke residue on the transom. I still have to wax-clean the transom after 4 - 6 hours motoring, but it gets my carcass off the boat at the end of the day.
We have an R&D (PYI) nylon coupling and an M&S Spurs line cutter on the shaft with plenty of room. I would definitely haul the boat to do the installation in case you needed any machining.
Good Luck, DAS,