[SpudRider]

Wow! 8O That's more damage than I expected! :?

Fortunately, you might not need a new cylinder head. As long as the inside diameter of the camshaft bearing has not been damaged, you can smooth out the damaged area of the outside diameter of the bearing. You can also smooth out the damaged area of the cyclinder head, since the camshaft only turns on the inside diameter of this bearing. If the inside diameter of the bearing is damaged, you can purchase a new bearing along with a new camshaft.

Weldangrind is familiar with a modification performed on TW200 cylinder heads, which should also work on your cylinder head. For this modification, you would once again smooth out the damaged area of the cylinder head which supports the camshaft bearing. Then you would install a sealed, ball bearing which has the same diameter for the inner race as the diameter of the camshaft. Once again, since the camshaft turns only on the inner race of the bearing, the damaged, outside diameter of the cylinder head is irrelevant.

However, it's important to keep a tight fit between the camshaft bearing and the cylinder head, so the camshaft won't wobble. If you don't want to perform either the repair I mentioned, or the modification, you will need to purchase a new, ZS250GS cylinder head. I don't think any Yamaha cylinder heads will work for your ZS250GS, since the Zongshen cylinder bore is larger than the XT225 cylinder. :?

Spud