1989 Formula 242ss/7.4l Prop??
 

Ok guys, i'm running a 330hp 7.4 liter in my 89 formula 242ss currently have a 21p stainless mirage prop. I'm getting exactly 50mph on gps on calm water at 4200 rpm, but not trimmed fully out. If i trim out further i gain rpm to 4600 but i lose speed. Anyone found what works best on this old tub of a boat or have any suggestions? I was considering taking the prop in and having some cupping added to the ends of the blades so it grabs the water a little better when i trim up, hoping this will get a little more of the boat out of the water???

At 4200 you are hooked up quite well! Do what you are thinking, use the prop you have, have the cup added "correctly", get some trim, rpm and more speed!

Your boat will thank you.

Brett

I have a friend that had one of those.
He ran a 19p Mirage plus.
The boat topped out at 52 running light.

Thanks for the replys, especially you brett. I'm new to this site and the i/o boats. Sounds like you know your props though. Where are you located and what kind of turn around on adding some cup and taking out a few dings if i sent the prop to you? my email is [email protected] if you prefer that.

Jake

I have a 242LS w/BBC and I run a bravo 1, 4 blade 22 pitch labbed slightly great day 55 gps. So you are not far off bblades I am sure can hook you up with a little extra.

seef158

I dropped you a email, sorry for the delay.