This is my first time porting a cylinder give me some opinions and tips

Can this cylinder be ran? Had what i believe was a coolant leak. Not sure if this is enough damage to warrant replating. No scratches I can feel. Only two piston and ring changes since the last replacing. App 15 hours each. We only do trail riding.

In the process of bringing back my 1988 kx250f back to life, I gave it a well needed set of sprockets and x ring chain. It has not been even 15 hours on that chain and almost every time I go out, i find that my chain is more slack than when I started. A couple of times was due to my own fault...

Ones I see on eBay are cracked and jacked up. Anyone want to sell or even trade for engine case halves?

I have a 1988 KX250F and developed a leak from the countershaft. I took the collar and o ring out to clean the area assuming some sand was preventing it from sealing. the collar has a crack going completely though it. Normally this would be no issue to fix for me, but currently there are no...