I am looking to buy a used force 150hp runs good. compression is 120psi equally per cylinder,trim works very good looks well maintained, but #1 cylinder piston has a impression of the spark plug hitting but no other aparant damage he won't take under $1000. What could the impression be caused from? And is this a fair price? <br />also is ok to replace a force 1989 125 with this 1990 force 150 for 1989 bayliner 19'11" with cudy cabin.