2000 2520MV REPOWER 2017 YAM XBF250

[warthog5]

Sounds like 2in less pitch will bring your right where you need to be. About 5900RPM

1in of pitch is worth 200RPM.

But wait!

That motor is mounted all the way down. Where did the anticavation plate ride in the water?

Did you look? Raising the motor will free the boat up.

The motor's RPM will be higher.....The boat will be faster...... Your fuel millage will improve.....

Put 18in wide tabs on it.

I'd do that first and raise the motor 2 holes..... Then go test it.

 

[jpg1969]

What prop are you running? I have the identical hull with a 4.2L F300 and running a Yamaha SDS 15-3/4 x 15 prop hitting 5900 RPM.

 

[dadsdayoff2]

Hi guys,
The anticavataion plate is a hair below the keel, which is where I'm told it should be and also same as old factory rigged motor?
The prop is a stainless 17", really don't know much else.
Jim, what's your speed and mpg at 4K and what's your top speed with your 300?
From what I read on the prop data base thread on here, it seems my motor is dialed in pretty close to optimum range.
The dealer/installer was really impressed with my initial test and feels with a little more trimming I could of got my rpms up another 100 or 2.
Remember I did hit 41.9 mph and my cruise speed @4k jumped 50% to 27-28mph

 

[jpg1969]

F300 4.2L 2002 MVSC Notch Transom
3 Blade YAMAHA Saltwater Series with SDS 15 3/4" x 15
3500 RPM 24mph 2.4mpg
3800 RPM 28mph 2.6mpg
4000 RPM 31mph 2.5mpg
WOT 5900 RPM 42mph 1.5 mpg

 

[dadsdayoff2]

Hi Jim, thanks a lot for the info! My numbers are exactly the same as yours with the exception of your cruise speed is 3mph faster with same mpg, guess that's those extra 50 horses. Surprised those 50 extra horses didn't give you a higher top speed than the 250? In any case your numbers confirm my setup is close enough for me.
Thanks again, Ken

 

[jpg1969]

Good luck with the motor! With a modified vee hull, since more of the hull will not rise out of the water as you increase speed like a deep vee hull you are fighting a losing battle with drag resistance. I think that's pretty much top end for our 14 degree hulls +/- a few mph which is plenty for me.

 

[dadsdayoff2]

Thanks and good luck to you as well!

 

[warthog5]

The anticavataion plate is a hair below the keel, which is where I'm told it should be and also same as old factory rigged motor?

Totally disagree. Factories have always mounted them to low and that's to low. Even with or up to 2in above.

BUT......Your numbers are not bad..... Your top speed is about where a medium V hull is maxed out.

Yes you can overspeed a med V hull. They do not like and are scary at and above mid 40MPH. [with any kind of non slick water. It's just the way they react.

 

[pparke]

I am thinking about repowering from a F225 to a F300 on my 2510. Can you give me the name of the company you used for the repower and are you happy with the job. Thanks, Paul

 

[dadsdayoff2]

Hi Paul, I used sandpiper marine in Accomac VA. So far love the motor and am very happy I did the 250, I think the 300 would be overkill for me. Good luck

 

[dadsdayoff2]

Ran new engine 40 hrs last week for Trophy Striper season. Although fishing was off, the new motor is a beast.Here are some numbers- 3 adults, 5/8 fuel, gear and flat seas.
3800rpm-25mph-2.75mpg
4000rpm-28mph-2.5mpg
4200rpm-30mph-2.4mpg
5500rpm-42mph-? mpg
Motor is mounted one hole from the top and I would like to raise it one hole to see what it does. The dealer said to leave it be, and honestly I haven't seen numbers on here any better. So maybe I should just leave it be? Super pleased with the engine, hope it last as long as the old one.

 

[dadsdayoff2]

Some pretty Stripers we got last week