Opinions on cylinder


Local time
3:26 AM
May 19, 2023
So according to ebay my piston arrives in a few days. I took out my case bearings and seals to go and buy new ones and cleaned everything up in the bottom end. When i got to the cylinder to repair the exhaust stud threads i noticed a little gouge above the transfer port. You can roughly feel it with your nail.
Now putting new rings into this cylinder i feel like it would wear really fast. The piston was in a really bad state but it still had good enough compression. Do i just install the new piston and run it like this or do i take it to a machine shop to just hone it a little bit or can i hit it with some sandpaper? I would buy a new cylinder but i cant find one for the YD100 and the LD100 rebuild kits are almost as much as an entire complete engine.


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Ive never been a fan of the 1 peice cylinder and head kits, having had two seize and chip on me before, if the piston and ring kit is cheap, and you are not relying on the bike for transport, I would just run it untill something fails, i'm not an expert but im not sure if there is any way to hone or repair a plated cylinder
I’ve lightly sanded lines like yours and run it. Just be sure the line edges aren’t sticking up higher than the cylinder wall.
I’m running one now that has over 2,000 miles and my groove was a bit bigger.
I don’t know I it affects performance because I can’t tell by the power.
It’s probably not the best solution because the more area you sand that’s more coating or plating getting removed. My cylinder is Nikasil coated. I used a small stick with sand paper to get just the ridge.. or at least as close as I could without sanding out and away from the damage.
Looks more like the coating came off and scratched the cylinder. If that's the case, the rest will fail too.