Re: Single prop VS Duoprop questions.
Well, we tested the new tach with a Snap-on digital counter straight off the crank. At max RPM the difference was within 100 RPM. Happy am I.
Today I added a 240 LB helper to the passengers seat for a retest of the 15x17 prop.Total 460 LBS of Humans. It took a 9 second count to get it to plane, and our WOT was closer to 5500 rpm with the extra body. Top speed still around the 32 MPH mark using the GPS for speed counting.
We did the test over a few times, with consistent results.
We went in to the Brechin launch and switched to a 15x19 prop.
This was a terrible prop, and you could have a beer and a smoke waiting to get this to plane. It was laboring the whole way through, with a WOT 5000 RPM at 33 MPH...
The engine was way happier spinning the 15-17. We switched back to the 15x17. She's a keeper.
Bottom line, the prop guy in Nanaimo may not be the best guy to use for your prop repairs. After chatting with my marine mechanic. he confirmed this, with a couple examples of poor repairs done.
(My re-vulcanizing by him didn't last a year...) BUT his service was fast. :> He did recommend a name to use. Private email me for it.
I am fortunate to have a good mechanic who lets me test the props and return them till I am happy with my selection. I am still going to have him keep an eye out for the duo-prop bottom for me, but I am happy that the poor performance cause has been determined.
Time to get fishing...
