Johnson 9r69s no spark.

[GLEN DEUTSCH]

This is driving me nuts.Motor ran great wot but would not idle. Cleaned the carb really, really,really clean. Started and idled but stalled out at wot. Ran well at 3/4 throttle. Back to the shop. Cleaned the highspeed jet. Started in the tank and got lower cylinder not running: upper OK. New plugs. New condensers.New points. Both coils test 7 0hms. Replaced coils anyway. New plug wires. Timing set with multimeter. Points gently filed (no sand paper) and cleaned with lacquer thinner. Sometimes get weak spark but not enough to start. Mag plate grounds to block. Very little mag plate wobble. Kill switch removed from points. Help.
Glen

[outbdnut2]

How weak is that spark in the dead cylinder? You may have enough spark with all the stuff you replaced, but that cylinder could have a broken reed, or some dirt stuck in a reed keeping it from shutting completely; or low compression maybe due to a blown head-gasket.

You could have gotten a bad ignition part – you can try swapping condenser, coils, spark plugs between cylinders, but do it one at a time, so if the problem moves to the other cylinder, you will know which part is bad. It’s rare, but I have had bad condensers, coils, and spark plugs new out of the box. An ohm test on a coil will not tell you if the insulation is breaking down, bleeding the spark off to ground somewhere, like to the coil core.

Good Luck!
Dave

• This reply was modified 4 years, 11 months ago by outbdnut2.
• This reply was modified 4 years, 11 months ago by outbdnut2.

[GLEN DEUTSCH]

Thanks outbdnut2. Compression is good. Will try again by switching one part at a time.

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