Re: 1954 Johnson QD 15 Wont Start after running
of course bad gas could be the culprit. you check easily enough by preparing a fresh batch of fuel/oil mix. you'll want to do 16:1 for this model. assuming that's not the case, you may be getting spark, but not enough of one or a very consistent one. the spark should easily jump a 7/16" gap and produce a bright blue-white spark with an audible "snap" and the smell of ozone. you can get a spark plug gap tester at an auto parts store for about $7. You'll know if the coils bad when you remove the flywheel and visually inspect them. the coils were about the only weak link on these old motors. over the years, the coils have usually replaced as they fail. however, it is possible that you still have the original coils. only way to be sure is the take a look. assuming they have been replaced at some point, they're probably ok. you'll know if they're replacement coils if they have a solid, smooth plastic coating, usually green, black, or red. that really only leaves the points and condensers, which are "consumable" components ad are designed to be changed periodically. a tune up kit with new points and condensers is probably your best bet for getting a strong, consistent spark. Here's a pic of what and ideal electrical system (magneto) should look like when you remove the flywheel. Let us know what you find and feel free to asks more questions. we like pics too.
