thanks for the advice! I really have no idea what I'm looking for in this thing. a crank rebuild would still be far cheaper then a entire new crank.

I am able to move the power valve, (by using the adjustment knob) there is some scaring around the centers of the two cases where the crank would be. It did come with a pretty intact piston but thats not to say that they didnt replace a bad one.

Is a melted piston what would cause the dome to be all scared up?