No spark

captain oblivious

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I recently came to visit my daughter and she said her lawn mower will not run first I replaced the spark plug still no spark then I pulled the pull rope cover off and inspected the coil found that it was Rusty apparently been leaving it outside so I've replaced the coil clean the flywheel and still no spark any help would be appreciated
 

Bertrrr

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Did you set the gap on the coil / magneto ? Not sure what the setting is but probably .010-.020 or thereabouts to start and see if it generates a spark,
 

mechanic mark

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Drain gas from tank, fill with fresh gas. Recheck spark plug gap at .030. Did you gap coil to flywheel at .010 with business card? Remove & inspect flywheel key at crankshaft. Clean underside of mower. Adjust valves to specs with engine cold. Check oil level on dipstick & smell for gas in oil. Please report back with engine make, model, & serial #'s, thanks Mark
 

captain oblivious

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Did you set the gap on the coil / magneto ? Not sure what the setting is but probably .010-.020 or thereabouts to start and see if it generates a spark,
I set the air cap at 14 and unplug the kill wire in case it was rubbed through somewhere I am completely baffled magnet on a flywheel and a coil and it should make spark but it doesn't
 

bertsmobile1

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If you are old enough you will remember points & capacitors which were an eternal problem on mowers
Well in 1962 quality mowers replaced the points with a Hall Effect Trigger
American mower companies were too cheap / stubborn / nationalistic to replace the points till around 1990 when the Australian patient ran out .
For the next few years they used an external trigger unit then some smart arse worked out they could embed the chip into the coil and change the coil from a $ 5 part to a $ 50 part which was a good money maker as the chip cost 25¢
So if you remove the kill wire & you get no spark then either the cap on the spark plug lead has gone bad or the chip has gone bad

PS rust on the flywheel & / or ignition module ( previously called a coil ) have zero effect unless it is thick enough to touch together as the magnet passes the magneto legs
Having said that corrosion between the mounting plate & the ignition module can cause a bad ground but is the 12 years I have been doing this for a living I am yet to find this to be a problem unless the engine was stored without the magneto module in place .

So if you have no spark with the kill wire off , time for a new module
 

Tiger Small Engine

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If you are old enough you will remember points & capacitors which were an eternal problem on mowers
Well in 1962 quality mowers replaced the points with a Hall Effect Trigger
American mower companies were too cheap / stubborn / nationalistic to replace the points till around 1990 when the Australian patient ran out .
For the next few years they used an external trigger unit then some smart arse worked out they could embed the chip into the coil and change the coil from a $ 5 part to a $ 50 part which was a good money maker as the chip cost 25¢
So if you remove the kill wire & you get no spark then either the cap on the spark plug lead has gone bad or the chip has gone bad

PS rust on the flywheel & / or ignition module ( previously called a coil ) have zero effect unless it is thick enough to touch together as the magnet passes the magneto legs
Having said that corrosion between the mounting plate & the ignition module can cause a bad ground but is the 12 years I have been doing this for a living I am yet to find this to be a problem unless the engine was stored without the magneto module in place .

So if you have no spark with the kill wire off , time for a new module
So you said you have replaced the coil and still no spark. Did you order a new coil based on the engine model number? Do the new and old coil look pretty much the same? Have you tried checking for spark with and without kill wire? Have you tried a different spark plug?
 

captain oblivious

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New plug
So you said you have replaced the coil and still no spark. Did you order a new coil based on the engine model number? Do the new and old coil look pretty much the same? Have you tried checking for spark with and without kill wire? Have you tried a different spark plug?
I purchased a new plug still no spark I called the local small engine shop gave them the model number of the engine they had a new coil I took the old coil and compared them identical still no spark
 

PTmowerMech

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New plug

I purchased a new plug still no spark I called the local small engine shop gave them the model number of the engine they had a new coil I took the old coil and compared them identical still no spark

That mower is haunted. I suggest you take to your local priest and have a priest perform a exorcism on it.

How are you checking for spark?
 

captain oblivious

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That mower is haunted. I suggest you take to your local priest and have a priest perform a exorcism on it.

How are you checking for spark?
The last time I literally stuck a screwdriver into the plug wire and held on to it didn't get the least amount of shock I've never seen a bad flywheel but that's where I'm at it's still magnetic I have no clue why this thing is not getting spark and yes it very well could be cursed
 
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