I was doing some trail riding this past weekend and was coming up to a small hill in 2nd when the engine just immediately shut off and locked up. I was able to push the kicker down once but once it came back up, it was stuck. I bought this bike last summer and the PO could not tell me how many hours were on it. Everything looked great - clean oil, clean radiator fluid, good chain, good valve clearances. I checked everything and put an hour meter on so I would at least know how many hours I have put on it. It always ran strong and no out of the ordinary noises as far as I could tell. I have put exactly 6 hours on it this spring.
Now, to be honest, I found some magnetic shavings in the filter the last time I changed the oil. Not a lot but enough to show up on my magnet pen. I was hoping maybe transmission gears or something. Just a small amount, no gold flakes or anything. So my mistake, I should have probably torn it down immediately.
Anyway, I started the tear down last night. I have not removed and split the bottom end but the head and cylinder are off. The head looks fine, the cylinder has a small scratch on the exhaust side (I'm not sure if it is from this incident or not) but the rod does not spin freely on the crank so at least the big end bearing is shot.
Not knowing how many hours were on the bike, I think my plan is to just go ahead and replace the crank with a new OEM one, do a cylinder/piston swap from MT, and replace the cam chain. Is there anything else I should do while I am in there?
Here is what I found in the filter cavity: