Opinion on crank journal..

rk970

Seaman
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Jul 15, 2013
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71
Journal is smooth and mics on specs, not oval or tapered.. Is this ok to use?
 

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GA_Boater

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What is the crank out of. Plain or roller bearings?
 

rk970

Seaman
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Jul 15, 2013
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125hp 4cyl force outboard, 2cycle cross flow, roller bearings
1258X5A
 
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Nordin

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Jun 12, 2010
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2,428
Not 100% okey but I should go for it if you do not have put a lot of money in it.

If you have rebore and put in new pistons ...... look for a better used crank.
I would not be satisfied with that crank with a rebored block and new pistons.
 

rk970

Seaman
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Jul 15, 2013
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71
I decided to try to find a better crank.. The force 125 crank part #FA528018 has been superseded to part # 817400T3
I found a local crank from a 1992 force 120, when I looked up the part number for the crank it is 817400T3. I cannot confirm anywhere if the stroke on a 1992 120 is indeed 2.875". I went and looked at the crank its in perfect condition with all bearings and he is asking $60 for it..
Can some one confirm what the bore/stroke on the 1992 120hp are, it is a 15 spline crank and it has the force lower unit.
 

jerryjerry05

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May 7, 2008
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You'll need to get the factory manual to find the stroke.

​IF??? my memory is right 1992 they used 2 different size pistons.
The crank can be used on 1990-1994 model blocks.

I would bet the 90's crank is the 2.875

The manuals I have show the 86 is 2.80 and everything in the 90's is the 2.875

​BUT!! I don't have a manual for the 90's 120.
​I'm comparing a manual for a 86/125 and a 90's 150.

​The old crank: does it catch a fingernail in the holes when you touch it?
​From the look?? If it doesn't have ridges on the holes? It should be ok to use.
 

rk970

Seaman
Joined
Jul 15, 2013
Messages
71
You'll need to get the factory manual to find the stroke.

​IF??? my memory is right 1992 they used 2 different size pistons.
The crank can be used on 1990-1994 model blocks.

I would bet the 90's crank is the 2.875

The manuals I have show the 86 is 2.80 and everything in the 90's is the 2.875

​BUT!! I don't have a manual for the 90's 120.
​I'm comparing a manual for a 86/125 and a 90's 150.

​The old crank: does it catch a fingernail in the holes when you touch it?
​From the look?? If it doesn't have ridges on the holes? It should be ok to use.
I measured the stroke on my 1985 125hp (1258x5a) at 2.87* I have a 908h4b (84 4cyl 90hp) and that stroke measured at 2.80*.
I cleaned the rod journal and main with 800, then looked at it under 20x magnification. There are a lot of pits, some areas I can feel "catch" with a finger nail.. Some areas between the pits have what look like micro fracturing of the surface. The rollers and bearing shell from that main have the same appearance.
I have done some mild porting on the transfer ports and a new set of pistons going in. I just got a bad gut feeling on running this crankshaft..
 

kbh121956

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Jun 30, 2013
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474
I would go by your "gut feelings" And try to find another crank.
 

jerryjerry05

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Now the tough part, trying to remember that!!

​I can remember pretty much everything I did up until I hit 55 .
​Now!! I can't remember what I had for breakfast!!!! :)
 
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