I need some help, We just bought a 450 John Deere with a six way blade. I think it is a 1969-72 not real sure. I used it for about five of six hours,and it started loosing power and making a loud knocking noise. This is a 202 diesel turbo four cylinder.
I can still start it ,but it requires WD/40 To get it going. I am going to do a compression check, but I think I have a bad piston maybe??? Any thoughts?