25 HP on 4 meter sib how fast

[Andynw]

I have an evinrude 25 hp till e-tec on a 4 meter Honwave, rigid floor.

Two up, about 30 stone, the max speed is 19 mph by GPS, (flat calm) is this what others get / would expect.

Every thing a full pressure as I have a digital pump.

Have run the motor 1st , 2nd and 3rd trim hole out best performance is with 1st hole but get a lot of spray, 3rd hole gives cleaner wake but less performance.

The cav plate is below the bottom of the hull by an inch or two, would this cause drag, thinking off experimenting wth a block on the transom to raise the motor?

Any other sibbers had similar issues?

Though would have got a bit more out of the, despite being a hefty lump.

Andy

[Festinghouse]

my first boat, a yam 360s with a merc25 gave me 26mph with 2up but dropped to 17mph with 4up.

[azzurro]

I believe 2 people on board 4 meters sib 25hp would be more than 20 knots WOT on best conditions (maybe 21-22knots). I get 20 knots on same config but only 20hp.
Depending on people weight and following seas overrev engine stops may happen.
Some kind of configuration is not correct: medium-sized leg? splash? weight distribution? First hole should not be the best.

[Peter_C]

I have a bigger boat with more HP and top out at 28 mph in heavy chop. Goes much slower on glassy water at around 25-26 mph.

[Sharkbyte]

I'd expect a little more than that, to be honest.

[PeterM]

Bombard 380 with a 25 was getting about 22/23knts same set up ( 2 up etc ) - maybe a few more if I lifted the engine an inch ? So thats what 25/26MPH ?

[clydeoutboards]

Hi

do you have any pictures as this is low?

dave

[xs 400]

performance of a t40

my last boat was a t40, I had a 30hp yam 2 stroke short shaft with doel fins, flat calm i bottled out at 26 mph as with tiller steer it felt skitty.

Your issue could be ;

• under inflation of hull/tubes
• wrong propeller mine had a 9 7/8 x 13
• engine not tuned
• weight distribution
• trim angle (although 3rd was ok on mine) but i had no splashing

[d1ve1n]

hi with a 4.2 quicksilver and 25hp mariner we get 35 kph think that's about 25 mph i think
that's according to the gps
of course it feels much faster

don't think you will get much better

[Arctic]

Had a Zodiac GRMKII, would do around 22 knots but that had a 30hp Evinrude on it. Good fun anyway!