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I have the gear ratio resultsNot Good

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ejbtech1

Regular Contributor
"I marked my prop at the 12 o&

"I marked my prop at the 12 o'clock position, and my crank at the 12 o'clock position.
Two full turns on the crank, brought my prop to the 6 o'clock position.
So, this means I have a bigger outdrive than what I should have.
This is not turning out good. It tells me that I have an outdrive for a larger engine. Right?
AQ120B with a "supposed" 270 outdrive.
What am I looking at? Basically a half turn on the prop for two turns on the engine.
The prop, I had checked at a reputable prop shop today, and it is a 14x19.
HELP!!!!!"
 
"The propshop told me I should

"The propshop told me I should think about a 14x13 prop to get the rpms up and some speed.
They said there is something weird about my scenario. Someone before me has jerry-rigged the engine/outdrive, and I am confused in figuring this out.
I have come too far to stop now. So, away I go......HA!!!"
 
Where can I locat some numbers

Where can I locat some numbers on the outdrive to find out what I have? ANYONE????
 
"Eric, how many times did you

"Eric, how many times did you do the test? You may want to repeat it with the propeller locked (turn it clockwise until it does not move) and have someone witness outside how many turns has the prop turned after you finish doing your two engine turns. Alternatively, you can ask the person outside the boat to count one full turn in the prop and then you can count how many turns of the engine it took. This last method will be more accurate. The likely chances are that for every prop turn the engine does make either 1.61 turns, or 1.89, or 2.15. The latter (2.15) is the correct one for your engine."
 
I had my wife outside the boat

I had my wife outside the boat the whole time....tried it like 3 times.
The prop turns counterclockwise.
 
"course that's my wife....

"course that's my wife.....HA HA HA!!! Anyway, that's what we came up with.....make sense? or no?"
 
let me check again....I will d

let me check again....I will do it locked a half turn at a time right now......hang on.
 
"ok....two turns brings me alm

"ok....two turns brings me almost to where I started......so I guess I have the right ratio, right?"
 
"I think I made a mistake by &

"I think I made a mistake by "Bumping" the engine, it seems to not give an accurate result by bumping it a half turn at a time.
This time I turned it over two full turns, and it came back up where it should be.So, I guess it's the right ratio, wrong prop......right?"
 
"I am aware that the prop turn

"I am aware that the prop turns counterclockwise, but if you turn it clockwise after shifting into gear there won't be any slack left.

If your wife is right, then the gear ratio seems to be 1.35:1, which I have heard of but I am unsure of its application (diesel?). If this is what you have installed, it is definitely too heavy for your engine.

I suggest you repeat the test but counting how many turns of the engine takes to comple one full turn of the prop."
 
"Two turns on the engine with

"Two turns on the engine with the outdrive locked brings me back to right where i started, but I will have to be sure since you say a diesel turns different.............WHAT A MESS!!!!!
I actually think that I got is right by myself...... and it would be two turns on the engine.. brings me back to where I started. That makes the ratio correct for a 4 banger.
So I need a new prop with a pitch of at least 15, if not less. Correct?"
 
"This makes me wanna start dri

"This makes me wanna start drinkin the Jack Daniels we make her!!!! HA HA HA !!!!!!
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"
 
"If you really need a 14x13 sh

"If you really need a 14x13 short hub, I have an almost brand new one, used once. I tried re-propping from a 15x15 to gain 600-800 rpm and this prop dropped almost 10 MPH off my top speed and moved my WOT from 4K to over 6K. I think I gave about $150 for it. It's worthless to me so reasonable offers accepted.

200rpm per inch/degree did not work out for me.
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"
 
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