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I am rebuilding the forks on a 2003 YZ 250. In the process of cleaning up all the parts I noticed some visible scuff marks on the chrome that run up and down the length of the lower tubes in a few spots. They are not scratches, everything is super smooth and I can't feel them but I see them in the right light. I tried to take a picture but they don't show up.
Are these anything to be concerned with as far as causing an issue with new seals leaking?
If it's best to try and polish them out what's the best way to do that scotch brite or wet sanding? What grit?
The bike sat for a long time and the seals were weeping. I rode it once before tearing the forks down so I don't know if the one ride did this or not.
If you can't feel the scuffs, they should not be a problem with your fork seals or bushings.
You can grab a piece of green or light-gray Scotch-Brite and create a 60° cross-hatch pattern as you buff the tubes.
I do that by wrapping the pad around the tube and grabbing it with my left hand while I use my right hand to twist the tube as I push or pull it through the pad. If you twist and push at a steady rate, you can create a very good crosshatch.
Allegedly the light gray is about 600 - 800 grit while the green is about 600 grit.
I use the green in my machine shop and it does well for taking small imperfections out of hard-chrome on suspension parts and hydraulic rods.
There are a ton of those KYB 46U forks on ebay... If you decide that the tube is junk, you can probably find a good-used replacement set of forks for a very fair price. I believe the YZ125, YZ250, YZ250F, YZ450F all used the same basic fork for some of those years... Just check the lower tube part numbers.
Make sure to ck your bushings
I tried some green scotch brite with light pressure yesterday and it did not seem to do anything in my cross hatching attempt.
Since they feel smooth I am not going to get to aggressive and make things worse.
I ordered new seals and bushings before I tore them down.
Of course as soon as I took off the top caps the rubber bumpers crumbled into a million pieces so I ordered up a new set of them as well.
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