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More power from a aq131a

A

albernifisher

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"I just bought a boat with a a

"I just bought a boat with a aq131a and a 275 leg,14 1/2 by 18 prop. It seems to be a bit under powered,Is there any tricks to getting a little bit more power out of it?"
 
"Yes Gary ! First thing you wa

"Yes Gary ! First thing you want to do is remove that small motor and replace with a big block. I recommend a 502 GM.A 396 built to the Hilt will do the trick as well.....Happy Boating
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"what size boat? You should go

"what size boat? You should go with a smaller prop pitch............El pescador taught me that!
I have a 21 foot boat with, originally, a 14x19 prop. I went to a 14x15 and it brought this boat to life!!!!! Before repower, think about REPROP!!!!"
 
its a 21'trophy hardtop.Ve

its a 21'trophy hardtop.Very slow out of the hole and doesn't get up on plane till about 3300 rpm.Been a outboard guy all my life so I don't know if this is normal?
 
"what is the RPMs at WOT??? wi

"what is the RPMs at WOT??? with that size boat I would think that you would need to go bigger, on my 19ft AQ131A / 275 I am running a 14/19 long hub, and it does great, or if I am loaded down with people and going to pull a tube I have a 14/21 (poor top speed but gets her out of the hole mighty nicely with a tube) you can also try a 15/19 which I also have tried that worked out pretty good, what I have found is that the bigger the pitch the more hole shot you get but lose top end.."
 
"Uhmmmm...Bill K...uhmmm maybe

"Uhmmmm...Bill K...uhmmm maybe you got that backwards? LESS pitch will give a better hole-shot (pull up skiers) and MORE pitch will give lower rpms for the same headway. The first number in the prop is the diameter of the rotating blades and the second number (after the X) is the pitch in inches that the prop travels forward during one rotation. A smaller second number will take more engine RPMs to travel the same distance as a prop with a higher/larger second number.
Think of it as a manual transmission in a car/truck. a 14X19 prop is like second-gear, while a 14X17 prop is first-gear, and a 14X21 is third-gear. Changing to a 15" prop would be like installing larger wheels....You'd have to downshift gears (reduce pitch) to keep the same performance. So a 15X19 would be close to replacing a 14X21. Get it?
(Gotta make sure too much diameter doesn't interfere with the cavitation plate, trim-tab, or other portion of the machinery.)"
 
"No tricks that I know of, Gar

"No tricks that I know of, Gary. But one of the forum members (Javier Cubero) recently installed a Weber carb and he reported better performance than with the stock Solex. Also, you may have to trade some top end speed for better planing, as in my opinion your engine is too small for your size of boat. Have a chat with Gary at Rev Propeller in Stewart Avenue (Nanaimo, phone number 754-7122) and he will either rework your prop or lend you one or two props that you can try to see if with either of them your boat performs better. Tell Gary that Eduardo advised you to contact him. I found Gary as being the most helpful guy for this kind of stuff.

In any case, you would do much better with a V6 or a V8 Chev on your boat. Personally, I would not be using less than 200 HP for a 21' planing fiberglass boat. However, repowering can be opening a can of worms (been there, done that)."
 
sorry G A you are right I don&

sorry G A you are right I don't know what I was thinking about when I typed that...
 
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