Classic AquaSport

Aquasport Mechanicals - things that need a wrench, screwdriver or multimeter => Props => Topic started by: AquasportTiger on May 29, 2008, 10:34:51 AM

Title: 19-6 Engine Prop Pitch
Post by: AquasportTiger on May 29, 2008, 10:34:51 AM
I am re-powering my 19-6 1974 Aquasport with a re-built Yamaha 115.  The seller has offered a 15 degree stainless prop in good conditions or a new 17 degree aluminum prop.  i know that the stainless will hold up better which i plan to take, but wanted to make sure i was getting a prop with the right pitch.  Anyone have any experience with this and could give me some direction??
Title:
Post by: Capt. Bob on May 29, 2008, 11:15:39 AM
AT,
IMHO, only you can decide what prop works best on your boat.
What may work for one guy might not work for you.

There are too many variables at work here and the only way to sort them out is trial and error. Someone with a craft similar to your's and using it in the same manner (fish or ski, maybe just cruise) can get you close but until you actually run the boat, you won't know for sure.

Old school was to prop the motor to allow operation in the motor's max operational range (say 5200-5500 rpm) at WOT. This is a good starting goal.
From there you can look to achieve the best cruising rpm in relation to fuel consumption (a really big deal today) :cry:

I personally would take the 17, because it's new and start from there.
A lot of "propheads" on this Board. I'm sure they'll weigh in.

Good luck.
Title: Props
Post by: GoneFission on May 29, 2008, 04:11:02 PM
See if the seller will let you try both and pick the one that works best.  I would bet the 17 will be the better choice, but I would also pick stainless over aluminum.  

I also assume you have a tach on the boat to measure RPM.   :wink:
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