Hello, New to the forum. I have a 1979 V150 on a 20' bass boat. It has sat in my barn for 8 years. I recently told my son I wanted to give him the boat and we would pull it out and see what it would take to get it running. We checked and confirmed that the plugs were firing, removed, flushed, and cleaned the fuel tank, replaced the fuel line, installed a new fuel pump, and installed a new water pump. We had a new battery with below recommended cranking amps. We were amazed when the motor fired and ran. We shut it down after a few seconds due to not having any cooling water attached. The motor would then only crank slowly then not at all as if the battery was dead. We then purchased a new 820 cranking amp battery and tried again. Once again it fired and ran for a few seconds then would not crank again. We then removed the starter and had it checked and serviced at a recommended shop. The technician tested the starter on a growler and installed new brushes. We attempted to start the motor again. It will spin and fire on the first attempt after setting, but will not on a second attempt. If we remove the spark plugs it will crank great on the first attempt, and then not at all. Our compression check was good. Could this still be a starter issue? What could be internally wrong with the motor to cause these symptoms? Thanks in advance!
