Done with #@!! ProPulse

thataway · Posted: Sat Jun 30, 2007 6:24 pm Post subject:

I purchased a back up Pro pulse for the CD 25--and it will be a "get home" prop. I have a back up aluminum prop also (from another boat--not sure if it will repitch exactly, but the boat and engine were about the same size). I run a SS prop, on all of my boats (except the dinghy) and am really sold on them.

HOWEVER--I had a bravo III unit 300 hp I/O on another boat, with counter rotating SS props. I hit a 1" stick at idle speed--stalled the engine, and I didn't think much about it----until a few weeks later the engine would not start. It turned out, that the 1" stick caught between the counter rotating props, had knocked one gear tooth off the lower unit gears--and one tooth, leads to two teeth etc--eventually when I changed out the oil--out came multiple teeth!

I would not be surprised that the Pro Pluse hit a small object and that was enough to cause the problems--I have also spun the hubs out of props, but that is not always a guarantee that the lower unit or prop will be protected.....

james · Posted: Mon Jul 02, 2007 3:36 pm Post subject:

I am totally sold on the new "gummy bear" props that are out.
impervious to damaging anything in the lower unit, and as a neat side benefit, they don't taste all that bad either!

Laughing

James

Pat Anderson · Posted: Wed Jul 04, 2007 7:56 pm Post subject:

OK, the 15.5 x 15 x 3 AL (Quicksilver, a Mercury product I guess) prop is on, and the first test will be tonight when we launch at Blaine and cruise around Birch Point to anchor out in Birch Bay for the fireworks show. We shall see...the 14.5 x 15 x 3 SS Honda prop has done OK, am glad to have it as a backup, but it spins up to too high an RPM for any given speed, and I'm pretty sure WOT would take her right past the redline and blow up...

Dora~Jean · Posted: Thu Jul 05, 2007 2:22 am Post subject:

Don't know if this will help since I have twin 80's, but I'm running 3-blade aluminums (original with Yami's), 13.5 x 15P". I paid close attention to this last trip's run, at 4,000 rpm with 5 people, 3 days gear on board, and dive gear for two, my GPS speed was 14-14.5 knots. This seems to be on the 'knee' of an efficient plane, just a couple hundred more rpms the speed is up to 16-16.5 knots. WOT is slightly too high, about 6,000 rpms, but I like the torque at slower speeds for maintaining a plane in heavy seas without having to jocky the throttle.

Good luck with your tests Pat, keep us posted!

Pat Anderson · Posted: Thu Jul 05, 2007 5:16 pm Post subject:

Wowwie zowwie! Performance and economy are DRAMATICALLY better with the 15.5 x 15 x 3 AL Quicksilver prop compared to the Honda 14.5 x 15 x 3 SS prop! I will record some real numbers on the Gulf Isand cruise, but for starters, running to/from Birch Bay, 3800 RPMs are giving me about a 14.5 knot cruise and 4500 RPMs about 19 - 20 knots...

journey on · Posted: Thu Jul 05, 2007 9:38 pm Post subject:

Hey, Pat, what was the mileage? And how heavy were you loaded?

Boris

Pat Anderson · Posted: Thu Jul 05, 2007 10:54 pm Post subject:

I would love to answer that question, but our Navman is SO far out of calibration that I hesitate to answer. Relative improvement in economy was on the order of 30% with the new prop. As I say, I will have some real numbers after the Gulf Island cruise...