Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Correct Prop Pitch?

Posted by litespeed on 03/22/06 - 7:19 AM
#1

I am finally bringing my project to a close here the next couple weeks. I will be launching it for the first time next week. I wonder if it still floats?:o

My question is this...... I just aquired a real nice 35 HP Johnson for this boat. What is the correct prop pitch for this boat and engine combo?

The boat will be set up as a tiller until I get the seats and console built.

Is there a right way and a wrong way to mount the engine on this boat? Should it be mounted all the way down on the transom or should it be raised an inch or so?

Boat is a 1987 13' Sport (20" transom).

Thanks,

AJ

Edited by litespeed on 04/05/06 - 1:22 AM

Posted by litespeed on 03/28/06 - 6:00 AM
#2

I will have the engine out of storage Wed. or Thurs. this week. I'll post the current prop specs when I get my hands on it (if this will help).

If I had to guess I think it is probably a 13. I'm thinking that I may be able to run a 15 with the tiller set up and then go back to the 13 when the inside is finished and it is remote again.

Does this sound right?

Thanks,

AJ

Posted by litespeed on 03/29/06 - 1:53 PM
#3

Ok....

I put the engine on a test stand today.

The current prop is a 10/13.

Does that sound right?

I'm wonering if I should go ahead and try a 10/15....

AJ

Posted by Nobleskydiver on 03/14/08 - 8:39 PM
#4

Hi AJ,

Wow, I can understand your feelings.

These have and exchange program. Take a try and drop a call

Try this web site http://www.piranha.com/show_article.php?id=4
http://www.piranha.com
http://www.discountboatpropellers.com/propellers.php

From the saddle

Bill

Posted by CES on 03/15/08 - 9:07 AM
#5

I'm running a SS prop, 11-1/4 " diameter with a 15 degree pitch on my 40 HP Yamaha on my 13' Calssic BW. The set up works well for me and the boat really scoots along very nicely with an excellent hole shot.

Posted by moose on 03/15/08 - 4:33 PM
#6

Aj,

I tried the 15"SS on my '68 13 with a Nissan TLDI 40 hp. I could top out at 45.1 mph and it was WAY scary. There is NO turning at that speed and it is VERY unsafe. I had the prop repitched to 13" and I'm very satisfied with the setup. I top out at just over 40mph and it jumps out of the hole. I have ptt so that helps a lot.
Mike

Posted by Tom W Clark on 03/21/08 - 10:19 AM
#7

When determining what size and style propeller to use on one's boat you need to consider the following parameters:

- Outboard's wide open throttle range (WOT) or maximum recommended RPM ("redline")

- The potential top speed of the boat based on similar experiences of others with the same motor.

- The gear ratio of the outboard.

- The range of sizes and models of propellers typically used.

Because of this, it is of little use to use comparisons of different boats with different motors. The old 35 HP Johnson may use a different gear ratio and propeller diameter than the Nissan 40 or the Yamaha 40.

I used to own a Sport 13 with a Johnson 35 and a 10" x 13" prop sounds about right. In any case, it is best to trial the boat with the prop you have and gather some speed and RPM data and then go from there. If you can report back with such data, we can offer some informed opinions about what might be best for you.

Edited by Tom W Clark on 03/21/08 - 10:21 AM