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Crankshaft markings

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Anyone know what may have caused the markings on the crankshaft surface in the attached picture? Cannot feel it with finger nail, just seems to be discolouration.

Bike hasn’t run for 40+ years so I’m thinking that’s the cause, just looking for more experienced & knowledgeable people’s opinion!

Have found some scoring on the big ends, so will be replacing, just not sure if I need to worry about the journal faces.

Thanks in advance!Crank journal 1

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Just discolourisation. as long as the journals measure within spec the scoring is livable with but does tell you the oil has been dirty so fit a proper car type oil filter in the oil return pipe.

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I would give them a polish  and check that the rods can freely rotate with the new shells. fitted. You would think that new shells and a lightly worn crank would naturally have a running clearance. .Looking at your rod shell ends  ,it may be snug. The roller bearings will be perfect for a kiddies fruit box go kart.

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Thanks gents. I’ve cleaned everything up today so will sit down for a detailed measure up shortly. Initial measure of the journals was 1.4990”, but I didn’t measure at more than one place so far!

Doing a total rebuild so am looking at changing to  updated filter set up.

thanks 

 



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