Good day
Two years back I found a non running 1975 70 hp Johnson motor. I cleaned the carbs using the kits and replaced the Rectifier, coils and Power pack. To no surprise, she ran just fine. Late last summer, I found it would idle fine but would not power up. I used the boat very little after and only putting around fearing a clogged high speed jet. I felt confident it could not be electrical with all the new ele parts. It was also hard to imagine I had a fuel issue because I rebuilt the pump, all new fuel lines, new feed hose and tank.
I admit I did have one misshape before I noticed the issue, I hit a stump at a fast idle. It bent the prop a bit. Some time later after the lack of power, I removed the motor cover and noticed the top coil was very loose. I tightened it down but no change.
Now I have taken some time to get her ready for the 2014 season. Checked the compression with a new tester and get 135 psi and all 3 cylinders. Then the 7/16" spark gap test show strong blue spark on the lower two but nothing on the top one. I reset the gat to 3/16" and still nothing on the top cylinder. I have the spare coils from when I replaced them so I will determine if the new coil is dead. Hopefully the coil is the issue and not the power pack or something else!
I assume with the top coil being so loose, the ground wire connection under the bolt holding it on was a bad ground.
Can a bad grounded coil die prematurely? Could this condition also cause other issues with the power pack, stator and Timer base?
Thanks for any advice
Two years back I found a non running 1975 70 hp Johnson motor. I cleaned the carbs using the kits and replaced the Rectifier, coils and Power pack. To no surprise, she ran just fine. Late last summer, I found it would idle fine but would not power up. I used the boat very little after and only putting around fearing a clogged high speed jet. I felt confident it could not be electrical with all the new ele parts. It was also hard to imagine I had a fuel issue because I rebuilt the pump, all new fuel lines, new feed hose and tank.
I admit I did have one misshape before I noticed the issue, I hit a stump at a fast idle. It bent the prop a bit. Some time later after the lack of power, I removed the motor cover and noticed the top coil was very loose. I tightened it down but no change.
Now I have taken some time to get her ready for the 2014 season. Checked the compression with a new tester and get 135 psi and all 3 cylinders. Then the 7/16" spark gap test show strong blue spark on the lower two but nothing on the top one. I reset the gat to 3/16" and still nothing on the top cylinder. I have the spare coils from when I replaced them so I will determine if the new coil is dead. Hopefully the coil is the issue and not the power pack or something else!
I assume with the top coil being so loose, the ground wire connection under the bolt holding it on was a bad ground.
Can a bad grounded coil die prematurely? Could this condition also cause other issues with the power pack, stator and Timer base?
Thanks for any advice
