perfect prop

B

bburgin

New member
just spent 16 days cruising, the new prop 13.5 diameter 15 pitch, aluminum, yielded 3.8 to 4.2 miles per gallon the trip, I always turn the engine 4500 that is 20 to 21 mph, and the boat fully loaded! 90 Yamaha four stroke 2006 model, a Yamaha factory mecanic told me turning 4500 would yield the best economy, he was on the money
 
Haven't been able to get that bulkhead to work exactly right, even after multiple surgical procedures on it. :lol:

But thanks anyway. Still haven't given up on it, but I think leaving it like it is, without a bulkhead, will be best.
 
I agree 13.5x15 seems to be the perfect Prop for my 80 hp 22 cruiser as well. I wouldn't spend the money on stainless either, it's just not worth it.
 
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Our two aluminum 3X15X17 props are back on Lady KC
after the prop shop full adjusted the geometry, alignment, cupping, balancing, etc. etc. of both props.

We were back out on the water.......small chop.....
with half tanks of fuel
and half tank of water,

and noticed a major difference.

The sweet spot for the counter rotating twin Honda 135's

seemed to be.....4100rpm, engine tilt-up 3 bars, GPS=23.5 mph.

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bburgin":ttwz1lv5 said:
just spent 16 days cruising, the new prop 13.5 diameter 15 pitch, aluminum, yielded 3.8 to 4.2 miles per gallon the trip, I always turn the engine 4500 that is 20 to 21 mph, and the boat fully loaded! 90 Yamaha four stroke 2006 model, a Yamaha factory mecanic told me turning 4500 would yield the best economy, he was on the money
Click to expand...

That is phenomenal gas millage; best I’ve ever done was 3.6mpg on a 3 day 108mile weekend. I have the same prop but 90hp 06 Honda with carbs, but I generally run heavy. In addition to the regular stuff we usually have 5 weighted shrimp pots, two tubes with 1000 feet each of ground line, either 10 or 20 gallons of extra fuel, full water if it's more than 2 days, the dink on the roof, 2hp Honda, 9.8hp kicker, gear and food for three, 6 fishing rods and three tackle boxes, large cooler for the catch and smaller one for the food.

Granted the pots and line go over the side 20 to 40 miles out, but when we bring them back the line weighs twice as much wet. If we don’t take the pots it's because we are traveling way out so often take 30 gallons extra fuel.

I average close to 3.5mpg with an average cruising speed between 18 and 22 mph.
 
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