Prop Questions

[woftam1024]

I just repowered my '86 Pursuit 2600 with 2008 t/150 Optis. The motors came with 15 1/4d x 19p mirages. At wot it was only at 4200 rpm. Mercs prop selector site recomends 15 1/2d x 17p. Dose this sound correct? Dose anyone have experience with Mercs prop selector? Are they right on thier recomendations?

Thanks in advance.

[Chisox]

Tom W. Clark, where are you?

[cataholic]

Sounds like they are right and you need the 17s. You need to give some more info, but 4200 seems like it has got to be too low, even with a heavy load and not trimmed up.

[Albiemanmike]

What is WOT on those motors??? I would stick my neck out and say there is something else very wrong with your setup as going to 15.5 X 17 isn't enough to get you into the high 5,000's which has got to be where those motors need to be? I am not a prop expert so take it all with a grain of salt but I have done a fair amount of research on this for my own boat.

[woftam1024]

WOT is supposed to be 5250-5750. 4200 was trimmed up with light load, two people and @ 100 gallons of gas. I've been searching other prop sites since first post. Found one that let me enter model of boat rather than just weight. They recomended 15 1/4 x 15.

[ken2]

I'd go with a set of 15's.

Check the motor height. If they are too low, that can rob you of rpm, speed and economy.

Mirage Plus 15's are 15 3/4 diameter.

Thats probably an overkill, I'd try Enertia's. They are a little smaller diameter, and easier to spin up rpm.

No computer program that I know of kicks out the correct prop. They will get you close, or a good starting point, but thats about it. Mercury's selector just list every prop that will fit your motor and get close on rpm.

How fast are you going at 4200 rpm?

[ken2]

The reason I'm asking about speed, is your tach may be off.

Your 1500 rpm low which is HUGE.

lugging the motors that much, I'm amazed you got up on plane.

If it didn't struggle much to get up, your tach may be off, and your not as far off as you think.

[triumphrick]

Here is a site you can use to help dial in your props. Scroll down the page to "prop wizard". Enter the info and see where you end up. Good luck!

http://www.dansdiscountprops.com/

[woftam1024]

I was coming up on plane pretty well. The fastest I saw was 29. The tachs are 2008 as well and came with motors but may be off.

Dans Prop wizard is who gave me the 15s.

Motors are mounted higher than old ones. I was worried they might be to high. Didn't trust other person in boat to drive while I checked height at speed.

[rchanner]

The reason I'm asking about speed, is your tach may be off.

Your 1500 rpm low which is HUGE.

lugging the motors that much, I'm amazed you got up on plane.

If it didn't struggle much to get up, your tach may be off, and your not as far off as you think.

Is this Ken as in "PROP GODS" ken?