As promised, I pulled the head on the XL250. I couldn't get the head off so I pulled head & cylinder as a unit.
I had to get creative in figuring out a way to separate the head without damaging the fins. It was truly stuck tight.
Ring gap? Check! Yeah it's got some!
No wonder it smoked like a 2-stroke...
I measured everything I could and it looks like I'll be able to just have it bored .25 over.
Then I broke out the K5 and went for a ride.
I should have brought my gloves, it was a beautiful day but it was a little chilly.