Hope this doesn't get too long. I want to make sure I don't leave anything out.
1979 Johnson 15 hp. It overheated Sunday while towing a stranded boater in. By the time I noticed steam and mist comming out the "pee" hole the motor shut down. Removed the engine cover and lots of steam comming up. About 3 hours later, with motor still in the water, I tried to start it. It fired right up. I shut it down after a few seconds.
I have the overheating problem solved. Two weeks prior, I installed a new water pump and upon reassembly I pinched the grommet that goes to the copper tube that goes intothe pump. Put everything back together. Put it back on the boat. Two pulls and she fires right up and is pumping water like a champ. I let it run at idle for 5-7 minutes. Head is warm but not hot to the touch. Could keep my hand on there forever. Water comming out pee hole is cool.
Now at this point I figure I'll take it out for a spin on the river. I put it in gear and as soon as I twist the throttle in stalls. After many attempts to restart it this is the last time it has run.
Here is what I have done/tried.
Checked spark with tester.at least 7/16th spark.
New plugs.
Fresh gas.
Checked all electrical connections.
It is getting gas because after pulling it so many times you can see it work it's way out of the exhaust. plus the plugs then get wet with gas.
It won't fire at all when I spray a little carb cleaner in the spark plug holes.
In the event that I flooded it, I have taken the plugs out and let the thing dry out for several hours and then replace the plugs and try it. No luck.
I'm working up to a question here.... I tested the compression. 100 psi on the bottom and 80 psi on the top. Not good I know.
I know I'm at least looking at a head gasket and checking the head for warpage and cracks. But wouldn't the motor at least fire with those compression readings albeit run like crap?
Thanks in advance.
1979 Johnson 15 hp. It overheated Sunday while towing a stranded boater in. By the time I noticed steam and mist comming out the "pee" hole the motor shut down. Removed the engine cover and lots of steam comming up. About 3 hours later, with motor still in the water, I tried to start it. It fired right up. I shut it down after a few seconds.
I have the overheating problem solved. Two weeks prior, I installed a new water pump and upon reassembly I pinched the grommet that goes to the copper tube that goes intothe pump. Put everything back together. Put it back on the boat. Two pulls and she fires right up and is pumping water like a champ. I let it run at idle for 5-7 minutes. Head is warm but not hot to the touch. Could keep my hand on there forever. Water comming out pee hole is cool.
Now at this point I figure I'll take it out for a spin on the river. I put it in gear and as soon as I twist the throttle in stalls. After many attempts to restart it this is the last time it has run.
Here is what I have done/tried.
Checked spark with tester.at least 7/16th spark.
New plugs.
Fresh gas.
Checked all electrical connections.
It is getting gas because after pulling it so many times you can see it work it's way out of the exhaust. plus the plugs then get wet with gas.
It won't fire at all when I spray a little carb cleaner in the spark plug holes.
In the event that I flooded it, I have taken the plugs out and let the thing dry out for several hours and then replace the plugs and try it. No luck.
I'm working up to a question here.... I tested the compression. 100 psi on the bottom and 80 psi on the top. Not good I know.
I know I'm at least looking at a head gasket and checking the head for warpage and cracks. But wouldn't the motor at least fire with those compression readings albeit run like crap?
Thanks in advance.
