140 hp outdrive with 120 hp motor

OMC73

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This is my set up right now on a project boat I got. I haven't been in the water with it yet. The number on the out drive is 980308. Is this not going to work with my motor?
 

Scott Danforth

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only difference is the sticker. difference in the motor is 1/4" inch stroke
 

OMC73

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only difference is the sticker. difference in the motor is 1/4" inch stroke

Ok. I've been told there is a difference in the gearing between the 140 vs.120 outdrive and the way I understood it was that the 120hp motor is under powered for a 140 hp outdrive.
 

Scott Danforth

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Same outdrive, same gears, different sticker
 

southkogs

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Scott knows these drives better'n me, but I have the 140 and the 120 uppers with different ratios (19.20 & 16.20 respectively) like I put in your other topic. Lowers are all the same (15.23).

BUT - the 980308 number you have listed is one I can't find. I think it's the part number of the upper gear case housing, but I can't confirm that. So, I wouldn't be too convinced you've got the 140 gearing just yet. The difference in gear ratio (I think) is slight enough that you can re-prop if the boat doesn't perform well. If it turns free - run it.
 

OMC73

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Okay, well I suppose if I ever get the thing in the water we'll find out lol.
 

OMC73

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Getting ready to do the impeller on the out drive so I have the gear case off. I counted the pinion gear and it has 19 teeth. From what I'm reading it should have 20 teeth for a 120 HP motor. Sorry for beating a dead horse here but I thought I'd share what I found.
 

southkogs

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The pinion gear is different between the two, but I don't know the teeth count.
 

OMC73

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The pinion gear is different between the two, but I don't know the teeth count.
Maybe I called it the wrong name. I'm talking about the gear in the gear case that is turned by the ball gears. Well I can't get the link to work.
 

southkogs

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Not sure what your link was, but I know the gear. There are two different part numbers for the 120 and the 140 (and another again for the 165). I don't know tooth counts without looking for some pictures though - I can do that later tonight.
 

OMC73

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Not sure what your link was, but I know the gear. There are two different part numbers for the 120 and the 140 (and another again for the 165). I don't know tooth counts without looking for some pictures though - I can do that later tonight.
I got # 0979925 for the 120 and 0979855 for the 140
 

southkogs

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Teeth count is correct, as are your part numbers.

I didn't realize this before looking that they correspond with the gear ratio directly too (I've not broken into the gear boxes much).
 
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