1989 Johnson 150 GT on Fire

foreman33

Seaman Apprentice
Joined
Jul 25, 2002
Messages
47
I had my boat out on the river today and when I cut way back on the throtle i notice what I thought was steam coming out of the motor. I thought it was overheating so I decided to run it a little bit more to possibly cool it down. When I cut back on the throtle again steam which was actually smoke was coming out of the engine. I took the cover off and saw that behind and under the flywheel something was burning. I immediately put it out and thought everything was okay. I started the motor and took off again. Once more it caught on fire. I grabbed a bottle of water and poured on it and put it out again. Took off once more and again another fire. Put this one out and turned off the power switch which controls everything except the motor. Started back up again and just putted along at about 8-10 MPH. It never caught fire again but I had no tach depth finder and any instruments working since all of the are controlled by the power switch was off. I was about 20 mile up the river from where I launched so it took me quite a while to get back, but I made it without anymore fires. My question and, and I appoligise for the lenght of this post but I wanted to try and explain what had happened, is what caught on fire and was burning with a black pungent smell like a coil burning or wires burning? It didn't seem to have any effect on the motor running but I still took it easy the whole way back to the launch. If anybody has any idea what this was and what I need to check for to fix and remedy this problem I would greatly appreciate it. Again I'm sorry for the length of this post but I felt I had to explain what had happened.<br /><br />Thank you all.<br /><br />Mike :(
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: 1989 Johnson 150 GT on Fire

Foreman.... Your explanation indicates that the "Water Cooled Voltage Regulator/Rectifier" has shorted out to a point whereas it actually caught on fire (a rather expensive item).<br /><br />Due to its location (the powerpack sits directly over it), there's no doubt in my mind that excessive damage exists to the wiring in that area. I strongly recommend that you eliminate any power (voltage) going to the engine until you have it repaired.
 

foreman33

Seaman Apprentice
Joined
Jul 25, 2002
Messages
47
Re: 1989 Johnson 150 GT on Fire

Joe<br />Thanks for the quick reply. My next question is what could have caused this to happen and what if anything can i do to prevent this from happening again? Does this "Water Cooled Voltage Regulator/Rectifier" have any effect on the performance of the motor itself? The motor seemed to run okay. As i said i drove it about 20 miles after this happened, but not very fast. I was just glad to make it back to the launch. Would this be a difficult job for me to replace and approximately how much would this rather expensive item cost me? The wiring doesn't seem to be too bad. The bakelite or whatever is there is what seems to be have been burning. <br />Thanks again for the quick reply.<br /><br />Mike
 

seahorse5

Rear Admiral
Joined
Jan 24, 2002
Messages
4,698
Re: 1989 Johnson 150 GT on Fire

Were the wing-nuts on your battery loose or did someone ever connect a battery or battery-charger backwards? Was a battery every disconnected while the motor was running, or a battery switch turned off while running? Grab each battery cable and yank on it counter-clockwise, if it moves, there is your problem. Even if they are tite, they could have been loose at one time causing intermittent circuits and high voltage spikes while the motor was running. That is why OMC insisted on lockwashers and hex-nuts tightened with a wrench to fasten the cables.
 

Sand Bass

Seaman
Joined
Jul 17, 2002
Messages
68
Re: 1989 Johnson 150 GT on Fire

Foreman, I have read here that some v6 Johnson/Evinrude motors will trap air in the top of the block and cause top of motor to get hot and possibly catch fire. Not sure if this would be your problem. Maybe one of the experts here could comment on whether or not your paticular model was known to have this problem.
 
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