Thanks for the messages, i have read a fair amount of posts from houstonprop and throttle-up and have noticed they are very helpful and informative to all questions.

Thanks

Our Pleasure! Please feel free to call me if you have any other questions.

Julie

searay215
 

;)

Searay215 -

Here is another data point for you. I had a 21' Sea Ray cuddy with a 260 horse 5.7. I ran a 17p Stilletto 3 blade at 5000 rpm WOT which seemed to work very well (elev = 1400 ft). I tried a 19p in the same prop at 4900 rpm WOT and gained about 1mph but my hole shot fell off. I also tried a 19p Mirage and lost about 300rpm and 2 mph. The 17p turned out to be the best overall pitch, especially at higher elevations. Given that I had a lighter boat and slightly more hp than you, I don't think a higher pitch is going to work best.
Like was said earlier though, the only way to find out for sure is to determine your WOT, trimmed out rpm with a lightly loaded boat. If you are at 4900-5000 rpm, save the money and buy something else for the new boat!

:eek: :eek: :eek:

oops....before somebody else catches this.....

Sorry for the goof, Searay215. WOT range for the 5.7 Alpha 1 on by last boat was actually 4200-4600 rpm.

I'm not familiar with the 5.0 MPI but I am guessing that 4400-4600 will be your WOT target.

Too much coffee today:crazy:

Thanks Grog.

The 5.0mpi i have is 260hp and the boat weighs 3800lbs, not sure of the elevation here in Australia.

Will find out the WOT revs as soon as i can.

The weather has been a bit off lately.

Cheers.

Well i have taken it for a spin and WOT was 4000rpm and and around 45mph by the speedo.

I might have to check that the throttle body is opening right up and maybe adjust cable.

I'll keep you posted.

took it for another run WOT 4200 rpm with 2 people and 20 gallon fuel.

checked cables and throttle opens right up.

any other suggestions/thoughts much appreciated.

Thanks
Paul

searay215
 

read what 28ELIMINATOR SAY'S.

Also, I can make the Mirage 17 blow out of the hole quick and run like a 19 on top end,lets get your propeller delima taken care of.;)

There are Mirage plus (new)on e-bay for 250.00 just what you need.let me know if you need any help on this its all guaranteed 100 percent to your satisfaction.