Prop help

[TimC2520]

Waiting to hear back from Ken at PropGods but thought I would ask here also.

Switched to a 4 blade this year and yesterday had it out for the first time.

The engine is a 1999 Yamaha 225 OX66. Boat is a Parker, 2520 Sport Cabin, 14 degree deadrise hull. Engine specs says max RPM to be 4500-5500.
Original 3 blade Yamaha prop is stamped 15 X 17 - T. Max RPM with that prop was 5300 and a GPS speed of 35 knots.
With the new OFS4R16PCL200, on his recommendation, Max RPM is 4800 with a GPS speed of 30 knots. Both at 4 bars on the trim gauge. What do you think?

 

[Ludicrous40]

Curious what your goal was with new prop. 35 knots on a MV 2520 isn't horrible, but what is your average travel speed? Are you trying to maintain plane at a lower fuel burn?

From the numbers your got, I think you're a little low on the rpm side at 4800, but if in turn you are eating less fuel at travel, then maybe that is what you were after.....

 

[TimC2520]

I spun the hub on the yam 3 blade at the end of last year. I had it re-hubbed, but since I do not have a spare, I decided to keep the Yam as a spare and buy another prop. The 4 blade was recommended for more stern lift (less tabs). I don't have fuel management capabilities on the boat so can't look at that. I did talk to Ken and he was surprised the boat didn't like the 4 blade and there was such a loss in speed/rpm, etc. So I decided to chalk it up as a failed experiment and I am just going to return the Powertech and put the re-hubbed Yam back on.

 

[PKS1801]

Since this was apparently your first time out this year, it will be interesting to see if the old prop performs the same, or something else might have changed during the winter.

 

[warthog5]

What do I think? To much prop.

By the way...I had to go look that Prop up....It's a 4 X 15 1/4 X 16

It killed your RPM.

 

[TimC2520]

Since this was apparently your first time out this year, it will be interesting to see if the old prop performs the same, or something else might have changed during the winter.

Good point, I am going to put the old 3 blade back on there on Saturday and see what happens...

 

[TimC2520]

Well, she is happy again.