I picked up a free 1973 Honda 7.5. Really don't know anything about it. When I pull on the pull cord I get no movement of the cord. I have removed the pull cord mechanism and it seems to work well. The cord pulls easily and the "pawls" (I think that's what they are called) Come out when the pull cord is pull (mechanism is removed from the top of the engine). Where do I start? I am hearing terms like hydrology, seized piston and recommendations that I need to remove the spark plugs to see if the motor turns over.... help.