New 2520 Performance Q

[channel_surfer]

Hey guys,

We took delivery of our new 2520 yesterday. First pilot house, first 4 stroke, first parker. Very very happy.

Just had a question about the performance. This is a 2520 with a full tank of fuel (150gal). F225 on the back, I noticed that the engine mounting bolt is in the second hole from the top. 2 people on board, no coolers, no gear, no additional weight, brand new boat with brand new bottom paint.

At 4000 RPM, the in dash speedo and the handheld GPS both read between 20 and 22 mph.

Top end was about 5800rpm and about 33-34mph on the in dash speedo and GPS.

Seems a little low based on what I have read.

Also, I noticed that while underway on plane, the furthest I can trim the engine up without getting ventilation is about 1/4 of the way up the digital trim readout. The upper 3/4 of the trim range is useless. Is this normal? Engine has 7 hours on it now so WOT bursts were only about 2minutes at a time but the speed seemed to level off about 33-34.

I was expecting about 28-30 at 4000R (According to the older yamaha perf bulletin) and more toward 39 WOT.

Thoughts?

PS - Still love the boat, didn't buy it to go fast just want to make sure I don't have any issues here.

 

[channel_surfer]

Well, I've done some reading here (this morning at work.... ) and it seems that my numbers are pretty much right in line with other owners that have the 25' 16 degree hull with a 225 on the back. I also noticed that the data in the yami bulletin was gathered on a 25 mod v, with a bracket, and likely no bottom paint and a tailwind....

If anyone with a 25' 16 degree hull and a f225 cares to share performance numbers I'd be grateul. Thanks.

 

[Themis]

I have your boat (I assume 2520SL) with the Yamaha F250. I kiss 40mph at 5800 rpm's. I have bottom paint. I cruise 25 or 26 mph at 4,000 rpm's. I am surprised there is that much difference between the F225 and F250. I have heard it said that the F225 is more like 210 ponies, but never knew whether it was myth or real.

 

[channel_surfer]

Yes it is a 2520SL. Thanks for the input.

 

[Themis]

You will love the boat as well as I love mine. I would venture to say most of us do not run WOT anyways. We all will cruise between 25 and 30 mph, including you, and our fuel economy will all be near the same mark (some slightly better, some slightly worse). She is yours now and she will grow on you!

Best of luck.

 

[channel_surfer]

Like I said, I didn't buy a speedboat.

At 4000R it was pulling about 20-22mph and that was fine.

If I pushed toward 4400 it seemed to pick up a lot of MPH for the modest RMP increase, getting up to between 26-29 mph at around 4400-4500rpm.

My dad and I are both thrilled with the new boat, I just wanted to do a quick sanity check on the numbers.

PS - nice boat.

 

[DaleH]

First thing for sanity, is forget about speed for now and make SURE she is propped right. With 2 guys, normal gear, and 1/2-2/3rds fuel, I'd like to see her 200 RPMs off max. Most boats are OVER-propped in my experience - boat dealer pet peeve #1.

2nd - where is the OB ventilation plate in relation to the water exiting the hull? It should be at or right near the surface. Again in my experience, most boats have the OB mounted too deep, robbing efficiency, increasing drag, and causing all-around performance to suffer - boat dealer pet peeve #2.

3rd - Do not confuse TRIM range with TILT range. OB trim units use the 2 outermost trim cylinders, this is typically a 15-degree trim range only. If you move her with the motor OFF from full down and watch your gauge, trim UP. Once you here the trim motor make a different sound and the motor starts moving up faster, this is the TILT range. OB t/t systems are designed with a pressure bypass valve to prevent tilting a motor all the way out while under full load, but honestly, it ain't foolproof, and these newer t/t motors have so much oommmph, some can do it.

That said, if you can or need to trim out PAST the trim range, IMHO your motor is mounted too deep and you might have the wrong prop - boat dealer pet peeve #3.


Now to be clear. These points I am raising are FINE points to tweak the best performance out of your rig. Dealers do not have the time to do this nor do they know what prop you will select and some brands (meaning premium performance props, like Stilettos or Mercury Enertias) stay hooked up much better than stock OEM wheels. They prep their rigs to keep the average person out of trouble ... I would probably do the same if I were them!

Go for your proper RPMs first, make sure engine is broken in before doing ANYTHING, and then check some of this other stuff. Also, yes, it is said that a typical F225 is low on horsepower (could be as low as 202.5 and still be labeled a 225) and the F250s need higher octane fuel to be a true F250.

I think you got an AWESOME boat! You already realize you did not buy a speedboat, but you boat a SOLID built boat that will bring you home in seas that will bash other boats. Use her and have FUN!

Welcome aboard !