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Discussion Starter · #1 ·
I am trying to build a running engine out of two engines that i had laying around for 10 years. They were meant for parts, but I got a frame with title that I would like to use for a scrambler build. So, here we go.
No.1 engine has a bad block, but good looking crank, rods and bearings.
No.2 engine has a good block, but crank, rods and bearings dont look too good. My question: can I swap crank from engine No.1 into No.2 and leave the mains in No.2? Or should I try to transfer the mains?
Also, please look at my crank of No.2 engine. Maybe I can get away with just putting new connecting rod bearings in and call it a day?

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I can't see the crank very clearly in the photo but judging by the state of you bearing shell I doubt if the crank is fit for further work without some help from a machinist shop.

To swap in the good crank you should really use the mains bearings that go with and are mated to it.

I've had to swap in a few cranks. You need to fabricate a bearing fitter/remover.

The rear main can be carried over using the good cranks carrier plate.

You may be able to use the front bearing fitted to the bad crank if it is still good after having a rod bearing fail and if it measures up as a suitable size for the replacement crank. But it would be better off with the bearing it is mated to.
 

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82 GL500, 78 CX500
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In section 12 of the factory manual are instructions on measuring the crank and rods and the bearings. The bearings have a color coding. I see a BB on the crank. That means the crank and rod are the same size on that side. The other is a color coding that is on the edge of the crank or rod bearings. Some one who's done bearing replacements could give you a better idea. I would check over the factory service manual before doing anything though.
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Discussion Starter · #4 ·
according to the shop manual I need Yellow and Green rod bearings for the clean looking crank. The problem is I can only find the green ones to buy. My question would be: can I have a machine shop take some material off of the one side of the crank pin, so I can fit green bearings for both rods? Seems like the yellow ones are thinner than the green ones.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Might be better to have the shop cut down the green bearing.
 

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Discussion Starter · #6 ·
Hmmmm.....didn't know that was a possibility. Thanks
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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The shop should be able to tell you. I think it would be preferable to a step in the crank journal.
 
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