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Rick, Factory Authorized Trainer
Category: Small Engine
Satisfied Customers: 8057
Experience:  Outdoor Power Equipment technical trainer since 1990, covering eight states.
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why wont my lawn mower get spark

This answer was rated:

why won't my lawn mower get spark

Could be a number of reason, such as bad spark plug, bad coil, ground wire damaged and shorting to ground, coil not getting connection to ground through mounting posts, or a safety switch problem if it's a rider.


Give me a bit more information and we'll work through this.


What type of equipment and model/serial numbers? What have you tried?

Customer: replied 7 years ago.
have replaced plug,magneto,points and condencer on a toro model #20700 and still not getting spark

That's a classic machine you have there. It would have had a Tecumseh TNT100 engine on it. You've done the test with the spark plug out of the engine held against the block and saw no spark. Is that correct?


Can you tell me what distance you gapped the coil to the flywheel, and what you set the points at?


Does the flywheel have strong magnets if you try holding a screwdriver near them? It should pull a standard screwdriver dangled from about an inch.

Customer: replied 7 years ago.
yes i have done the spark plug test,coil gap is.013,points are.08 and have done the flywheel magnet test
Points should be at .020". Try loosening them and let's see what happens. Also be sure to clean the contacts with a piece of paper drawn between them to remove any residual oil.
Customer: replied 7 years ago.
have adjusted the points to .020 and still no spark

Check these two things also, please.


Make sure the posts are free of corrosion and the coil is getting good contact to the posts by cleaning both surfaces with a bit of sandpaper.


Check the engine kill wire to make sure it's not damaged and grounding somwhere it shouldn't.


I'll be logged out for a bit and back on later to continue if this isn't your solution.

Rick and 2 other Small Engine Specialists are ready to help you
Customer: replied 7 years ago.
I replaced the engine kill wire, the mower starts and runs good. Thanks for the proper point gap, coil and spark plug gaps too. The local Toro dealer gave me the wrong information. Thank you so much for your help.Smile
You are so much more than welcome. Thank you, XXXXX XXXXX a wonderful evening.