Prop selection

[Musky hunter 82]

So I recently bought a 17' Alumacraft with a 60hp Yamaha tiller on it, and am wondering if I should change the pitch of the prop.  I mainly bass fish, and troll very little, I do have young kids so in a couple of years I would use it for pulling them tubing.

Here's what I'm seeing; at WOT I'm running right at 4900RPM (about 29-30mph on GPS), at idle in forward gear I'm right around 800-900RPM (around 2.25 - 2.5 mph on GPS), the hole shot is really good.

Here's what I'd like to see, in order of priority; higher top end speed, slower idle speed (if this is possible without sacrificing top end speed), hole shot can stay the same, or if need be can be less (the hole shot right now is very good).

I'll try to get the numbers off the Prop I currently have and post them on here so I know what I'm starting with.

What do you  guys think am I asking for too much or is this reasonable? 

Thanks

[BoxMN]

Did you try raising the motor one hole? If you can do that without it blowing out in corners, it should help you on both sides. That would be the first thing I would try, if you haven't. More lower unit out of the water gives you faster top end, and troll speed would likely be the same.

But if you change the pitch for top speed (higher pitch) you likely will have faster troll. And your top end rpm would be lower... 

However, your top end rpms seem little low to me. But not sure what the rpm range is supposed to be for that motor. I would guess about maybe 5200-5500, meaning you might even be able to go down a little bit in pitch, which would raise the rpms and potentially pick up top end, and also slow your troll and increase your hole shot even better.... 

Only testing will really help. Not sure of that hp range of what different props are available, but even different shaped blades can make a big difference, at least on higher hp motors they do, and there are lots of choices. Our 150 has BIG blades on a Merc SS Tempest prop which is awesome, and on my 60 (merc four stroke, on pontoon) I have a merc Spitfire 4 blade prop (can't recall pitch but think 13") and this thing really gives the motor umph! We get 19-22 mph gps with a 22' toon (5200 rpm in hot summer, 5500 rpm in cold water). I know this prop is available in lots of pitches for lots of hp motors, and I would recommend trying it after seeing how it does on our pontoon, though it seems more a power prop than speed prop, so maybe not what best for you.

Good luck!

[delcecchi]

Which yamaha 60 is it?  Two stroke or 4?

Your WOT rpm look a little low, so going down a step or maybe even two in pitch will make things work better both in hole shot and top end.  

Props seem to be typically sold with 2 inch steps in pitch.  

Yamaha has a prop selector here

http://www.yamahapropselector.com/propSelector/web/

although I'm not sure how much help it will be.  

There are also "performance bulletins" at

http://yamahaoutboards.com/owner-resources/performance-bulletins

where you can look for something similar to your setup. 

A G3 17 foot tiller with a 70 two stroke had a 15 pitch prop and did 33 mph at 5900 rpm. 

There are also tests online at boattest.com where you maybe could find something similar. 

Or call/email soderblooms  http://www.soderbloom.com/

They have a pretty good reputation with props. Maybe they would recommend something. 

Edited August 30, 2016 by delcecchi

[Musky hunter 82]

Thanks for the reply's guys,

When I first bought the boat the motor was in the very top hole and there was a bunch of side spray and pull on the motor when going WOT.  I have had it raised up 2 holes so now the anti cavitation/ventilation plate is about 1/2" above the hull.  the spray went away as did the pull on the motor.

The motor is a 1996 Yamaha Pro 60 2 stroke, the WOT RPM range according to the manual is 4500-5500 (not sure why it's a range of 1000 rpm).

Do most places let you try out a prop before you have to buy it?  I hate to buy 2 or 3 props and turn out they don't work how I want them to.

Also the only writing I could find on my prop was. 16-K

Edited August 30, 2016 by Musky hunter 82

[delcecchi]

Then it sounds like you are already pretty close to the right prop.   You could go down in pitch one step, especially if the 4900 is with just you in the boat, or for towing tubes or whatever.

You might get a little bit more top end by dinging around with props, but not much.  

And there are some places that do the try before buy, or allow returns.