1971 evinrude 40 hp ski-twin 40152g

DaveN28

Cadet
Joined
Jul 20, 2015
Messages
14
I recently purchased this motor with a boat and the motor was running on just the bottom cylinder. So i bought a coil and that did not fix it. So thinking it might be a condenser i swapped the one from the bottom cylinder which was getting spark to the top cylinder and still no spark. After doing that and trying to clean the points with emery cloth i now have no spark on either cylinder. So for the top cylinder i can rule out the coil or condenser as being the culprit but it just doesnt make any sense as to why the bottom cylinder is not getting spark. If anyone has any ideas on what i should try i would greatly appreciate it.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
I suggest you remove the points from the motor and individually polish each contact shiny bright. Then reinstall and set gap to .020" at their widest opening.

If you want to eliminate possibility of any outside problems, simply temporarily disconnect both black wires that come from under the magneto plate. Those are the stop wires.
 

DaveN28

Cadet
Joined
Jul 20, 2015
Messages
14
I suggest you remove the points from the motor and individually polish each contact shiny bright. Then reinstall and set gap to .020" at their widest opening.

If you want to eliminate possibility of any outside problems, simply temporarily disconnect both black wires that come from under the magneto plate. Those are the stop wires.



I will give this a try, thank you for the suggestion.
 

newhamburgboating

Petty Officer 2nd Class
Joined
Mar 6, 2013
Messages
111
Almost every used motor like yours I have seen someone has mis wired the black kill wires on the vacuume switch. Running on one cylinder could also be a result of the vacuume switch being activated as a "run away" safety.
 
Top