How bad is this crankshaft...

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mamm7215

Petty Officer 2nd Class
Joined
Apr 28, 2010
Messages
184
So I've got my 140 torn down and am trying to assess how bad it was. Bought the boat a year ago knowing nothing so you know how this is going to go... Anyways had it out for a couple of days then cylinder 3 breaks a ring. Got a replacement 90hp (same year-'81) and spent most of the rest of the season making it work properly. I want to rebuild the 140 but now am wondering if it's worth it. The crankshaft journal for #3 piston is scored at the surface so now I'm wondering if it can be ground or is it worth it? The block will need a new sleeve and at least a rebore on the other 3 cylinders...crank.jpg
 
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mamm7215

Petty Officer 2nd Class
Joined
Apr 28, 2010
Messages
184
Re: How bad is this crankshaft...

I'm pretty sure #3 is shot but I'm taking the block to a machine shop to get proper assessment. The motor is already 0.030 overbored. #3 connecting rod has some "slight" scoring on the inner race. I mean just barely noticeable on the smooth surface. I'd still replace the rod anyways, it's the least of concerns right now...
I just pm'd the guy on e-bay to see what motor it's from...
 
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bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,306
Re: How bad is this crankshaft...

I got to believe that you should be able to find a better motor to start your project with than this 140..

1981 is old, so there are lots of other motors from the mid 90's back to 81 that you should be able to aquire cheaply...even if they dont run or need work...the crank needs work, you will have to get it reground, and then go with custom bearings...it looks like pitting...which tells me there is probably more pitting all over the inside of that motor, then you got a resleave, and boring and all new pistons.....you are gonna be into that motor DEEP$$$$$

use that motor for your Parts motor..maybe you can use misc parts here and there...there are probably more than a few models that share the same parts as that 1981 140 V4

plus you know that a 1981 140 HP is about as powerful as a 1987 125 hp!!!! because of HP rating changes

dont beat your head into a wall!!!

try and stack the odds in your favor of completing this project

good luck

bob
 
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boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: How bad is this crankshaft...

X 2....Don't even think about a rebuilt crank. They are junk.
 
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mamm7215

Petty Officer 2nd Class
Joined
Apr 28, 2010
Messages
184
Re: How bad is this crankshaft...

Yeah, that's my final conclusion as well. Considering someone's selling a completely rebuilt 82 115 locally to me for 1700 (top and lower leg according to poster). Not that I'm going for it, I'll just nurse my 90 along for now...
 
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