I got a 1964 3hp Johnson outboard that has not run in 28 years. It did not start at first nor did I expect it to, it had a mouse nest inside of it. OK, I pulled the gas tank and cover off, cleaned out all of the trash. I replaced the coils, capacitors and spark plugs. I could not get a spark out of one of the wires, so I replaced it as well. After this I cleaned out the fuel that had been turned to gel left in the tank. I took the silencer off and sprayed carburator cleaner into the butterfly valve. I then put it all back together and put fuel with Seafoam in it and it cranked right up. It ran pretty good at high speed but stalled at idle. It got really hot, when I splashed water on the head it turned to steam and sizzled. The engine also smoked alot.
OK, so I then pulled the lower unit and replaced the impellar, I am not sure which way the arms are supposed to bend. I made sure the pump worked by hooking up a drill and submerging the pump. It blew water out of the top but was effected by the turbulence of the prop. ( I am doing all of this in a barrel). I snaked the water line and blew air up it and it seemed open. On a whim I then pulled open the head and checked the water jacket which had water residue in it from when I had run it a little while before. The water jacket was clear of debris. I then shot air into the water return and it was clear as well. I replaced the head gasket and cranked it today. It ran pretty good but is still getting very hot. the little holed on the back of the lower unit are spraying out very little water (more of a mist). The engine ran smooth at higher speed but had a knocking sound at low speed idle range.
I am open to any help that you have!! I am really stumped as to what I am missing. I do not think their is a thermostat on this engine. Thank you for any help/advice anything.
OK, so I then pulled the lower unit and replaced the impellar, I am not sure which way the arms are supposed to bend. I made sure the pump worked by hooking up a drill and submerging the pump. It blew water out of the top but was effected by the turbulence of the prop. ( I am doing all of this in a barrel). I snaked the water line and blew air up it and it seemed open. On a whim I then pulled open the head and checked the water jacket which had water residue in it from when I had run it a little while before. The water jacket was clear of debris. I then shot air into the water return and it was clear as well. I replaced the head gasket and cranked it today. It ran pretty good but is still getting very hot. the little holed on the back of the lower unit are spraying out very little water (more of a mist). The engine ran smooth at higher speed but had a knocking sound at low speed idle range.
I am open to any help that you have!! I am really stumped as to what I am missing. I do not think their is a thermostat on this engine. Thank you for any help/advice anything.
