About 8 years old, and it started leaking oil at the head. I bought gaskets, took apart what I needed, including the valve rocker arms, and replaced the leaking gaskets. I reset the valve lash, it was slightly off on both. Now the engine is very hard to pull start, lots of tension on the pull rope, but it starts on the first pull, and runs fine.

Anyone know what the problem might be?

Is there a compression release that I may have screwed up?