spark / no spark

twocyclemania

Chief Petty Officer
Joined
Aug 10, 2010
Messages
505
To break the monotony I strayed away from the OMC outboards and decided to work on a couple of other brands; Scott (55) 5;Scott (57 or 8) 7.5 and an early 50's Elgin 5. I know the ignition systems are old but they looked good and I cleaned them up. With the flywheel sitting on top I spun both motors and was able to to get spark to both cylinders. However, the same phenomenon happened with both. With the Elgin I tightened the flywheel and thought I was good to go but found I had spark to only one cylinder. I replaced the plug wires. Still only spark to one cylinder. I worked on the Scott today. When I checked the motor it had spark to only one cylinder. I cleaned up the ignition and got spark to both. I went to test it one more time before tightening the flywheel and I'm back to one spark. I know everyone is going to say replace the coils and condensers. I'm trying to do this on a budget so I don't go overboard and put more into these than their worth. Anybody have an idea why I get spark sometimes and none at other times? Most likely cuprit between the coil and condenser? I'm not good at checking out electrical parts so I land up swapping in and out but I have a limited number of parts and it does get confusing. Does anyone else ever have the same experience? ps I have done the omc coil transplant to the Wico 5/8 field and it does work. If it's coils I can do that but the 5/8 field is a bit hard to find when you have the 7/8. I just like to get these little beasts to run but you can't beat the 50's and 60's OMC's for ease of repair, parts availability and reliability.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: spark / no spark

If we can assume the coils are ok, then 90% of no spark problems are caused by dirty or worn breaker points. Take them out, and take them apart and polish each contact shiny bright, individually. Then reinstall and set the gaps to .020" at the widest opening.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: spark / no spark

If you suspect the coils; swap positions and see if problem follows.Be sure the stator plate doesn't wobble.
 
Top