23CC Performance

[Chrisp]

I am Running a Yamaha 250hp fourstroke with a 19 pitch prop on my 1985 23 CC @ 5500 RPM WOT fullt trimmed out my top end is 40 MPH at cruise 4000 RPM boat runs @30 mph. Boat could use a soda blasting but that would be maybe A 2 MPH gain. Are these numbers OK? What height (motor holes) should I be at, mine is in the 2nd Hole.Appreciate any input.

[Wildman]

While the boat is on the trailer, take a 4ft level and lay it along the keel. Make sure the Anti cavitation plate is slightly above the keel (1/2in to 1in is normal). It is hard to say 'the second hole up' because there are so many slight variations on motors. But those numbers sound OK to me.

[junior11]

Is the engine on a bracket or not? I am going to have the same set-up on a 72 23cc with a bracket. I have a 19 pitch prop, I am thinking that the 17 pitch might be the way to go, it seems like you are struggling a little to turn 5500 if that is trimmed up and all. Plus I think your 85 is probably lighter than my 72.

[Chrisp]

motor is not on a bracket boat still has the original transom. A 17 wouild rev a little higher for sure I started with a 17 pitch should have kept it on there, seemed a little to touchy at the time.

[FishMagnet]

I was getting mid to high 40s WOT and a good 35 mph cruise at 4200 with a 225 Optimax prior to my remodel. Im spinning a 17 pitch prop

[Chrisp]

Cavitation plate is 1" below keel, is the performance gain worth the trouble of raising the motor ?

[Bigshrimpin]

Yes

[CaptLloyd]

Absolutely, YES! Before you do anything with your prop, you need to raise the motor so the plate is about 1" above the keel.

[Chrisp]

Dropped the boat off tonight at shop I am going to raise the engine 2 inches I am hoping I can gain 200 rpm's on top and drop my cruise down to 3800 rpm's @30 mph.

[eggsuckindog]

You will think its a different boat