QuestionQUESTION: My Murray riding mower with a B&S 12hp will not start due to no spark. I have replaced the spark plug & the arm/magneto with negative results. I have checked all the connections and tested the switches including the limiting and safety switches all are ok. But still no spark. Engine cranks well with fuel to the carb, just no spark. Can you suggest a possible cause?
ANSWER: Did you dis-connect the small wire on the ignition module and check for spark? Is the coil marked "This side out"?
How are you checking for spark?
Eric
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QUESTION: Yes I did and no spark. I put a new module on with negative results. I'm checking the spark by pulling the plug and grounding it against the block as I crank. The only thing I can think off is maybe the fly wheel key broke. Can that cause this problem?
Thank You
AnswerA sheared flywheel key will cause the engine to still produce spark...just not at the correct time.
Is the coil air gap set to .010-.012 of an inch? Just to be sure, there are no other wires attached to the coil when you check spark. When checking spark, with no other wires connected to the coil, you connect the spark plug to the spark plug wire, ground the tip of the spark plug to a metal engine part, and crank the engine. Is this correct?
Have you read this article?
http://www.briggsandstratton.com/support/frequently-asked-questions/Ignition%20S
Eric
