15hp Johnson - runs 5 min then stalls out

[gps_jetskier]

Anyone have any ideas? I checked the head temp as soon as it stalled. You could put your hand on it. It doesn't seem to be overheating. I bought and replaced the water pump. All parts looked fine though. I did find little rubber pieces in the exhuast area holes though. I'm not sure if they are from the motor currently or from a rebuild a previous owner might have done. It won't start after it stops. You have to wait a long time for it to come around. It will just spin and spin otherwise. It sounds like a gas problem, but everything checks ok that I know to do. THe carb screen looks good, and the tank pickup was clear too.

 

[JB]

Re: 15hp Johnson - runs 5 min then stalls out

Howdy.<br /><br />Sounds like a closed or plugged tank vent to me.<br /><br />Try opening the tank when it quits. If you get a "swoosh!" it is not vented.<br /><br />It could also be a "hot short" in your ignition system: a part that fails only when hot.<br /><br />Good luck.

 

[gps_jetskier]

Re: 15hp Johnson - runs 5 min then stalls out

I thought of the tank idea. It seems to be fine. A friend at work suggests the primer bulb. I think for the money I'll try that too. Not sure about the hot short. How would a person go about finding that? oh boy.....

 

[gps_jetskier]

Re: 15hp Johnson - runs 5 min then stalls out

UPDATE: I pull the lower unit off and tried to blow water u pthe tube. It just comes back out around the tube. I took the head cover off and pulled out the termostat and water will come out the hole there. If you apply water to the hole next to the thermostat, it just comes out around the copper tube, but not out the tube itself. If you try and apply water to the indicator hole it comes out around the copper tube, but again not out the tuber itself. I'm wondering if it's plugged up after the thermostat and that's whats not letting it flow. Any more thoughts?

 

[jray]

Re: 15hp Johnson - runs 5 min then stalls out

It sounds like your on the right track with the cooling system. I would continue to search for the blockage. I have a 15 hp Evinrude that was giving me the same symptoms. I was too late in replacing the water pump and the thermostat. Now its in the shop having the head removed to look for possible cracks.. $$$