New top end?

[happypizza]

I recently got my first bike, a 1985 yz250. After some tinkering it started up great. 1 or 2 kicks and it would fire up, but after it would warm up it kept stalling and was harder and harder to kick. Someone said they think its leaking oil and that I should replace the head gasket and change all the top end gaskets.

Wanted to get another opinion on this, and if thats the case where could I get the top end kit + head gasket.

Thanks!