Yamaha Stern Drive Prop Recommendation

[SteveO70]

I have the 5.7L V8 YEMS motor.. Im currently running a Stainless steel 14 1/4 X 19 3 Blade Prop. WOT with a little trim adjustment gets me to 4300 RPM..

Please let me know what you recommend to get the best performance...

 

[Maclin]

Re: Yamaha Stern Drive Prop Recommendation

What size and kind of boat is it in? What speed are you at with the 4300rpm?

 

[SteveO70]

Re: Yamaha Stern Drive Prop Recommendation

Its a 21 foot. Galaxie Ultra. Not sure on the speed. My speedometer has not been working. If I were to guess, around 45 or so..

 

[Maclin]

Re: Yamaha Stern Drive Prop Recommendation

To do prop calcs you really need accurate numbers for...:
WOT RPM
WOT MPH
Drive Ratio
Prop pitch

My first reaction is that the engine should be able to get to the max 4600 rpm in your setup. That prop is a good all around performer, should provide good holeshot and top speed of 45 or so.

What are you looking for exactly? Do you tow tubes/boards/skiers a lot? With lot of people and gear/coolers/etc in the boat? Or is it just 2 or 3 people and you want to get more top speed?

What is the state of tune for your engine?
Latest services performed?
Does it accelerate well from a dead stop?

Unless your boat is extremely heavy then I would look to the engine for that last few RPM's to get to 4600. In my opinion dropping down in pitch at this point could mask an engine power/tuning problem.