Briggs 17.5 opposed twin will not restart when hot 42A707

Before you do that.... you wouldn't mind posting the Type number of the engine? it's the numbers after the Model...
some of these engines used The coil, and points and condenser.
 
Here's a pic of the motor just because I was there. LOL Like I said before it's clean.
 

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Thank ya.... just uses the magnetron coil, and no points etc.
That number is the exact same as my opposed twin that i have too...
 
troynstan said:
If you lose spark when the engine is hot, it may be the coil overheating. It happens alot on push mowers. Although, if this is a twin cylinder, you would think it would at least run on 1 cyl. I would check for spark on both cylinders when cold, then again when hot and see if it is spark related. If you sprayed starting fluid in the carb when hot and it didn't fire, then it is either flooding, losing spark, or losing compression.
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the horizontally opposed layout uses a single double ended coil so one plug the spark goes from the inner to outer electrodes and the other sparks from the outer to the inner
These types of coils work really well on high reving things like transverse 4 motorcycles with battery coil ignitions but not so good on slow reving things like lawnmowers with magnetos
But of course they won't fire on either cylinder if the coil is bad, in fact the quickest diagnosis is to slip an in line spark tester on each cylinder then stand in front of the engine and watch for both testers flashing at the same time .
And you diagnose a weak coil if you get no spark at either end and then get a spark when you ground one plug lead.
 
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bertsmobile1 said:
the horizontally opposed layout uses a single double ended coil so one plug the spark goes from the inner to outer electrodes and the other sparks from the outer to the inner
These types of coils work really well on high reving things like transverse 4 motorcycles with battery coil ignitions but not so good on slow reving things like lawnmowers with magnetos
But of course they won't fire on either cylinder if the coil is bad, in fact the quickest diagnosis is to slip an in line spark tester on each cylinder then stand in front of the engine and watch for both testers flashing at the same time .
And you diagnose a weak coil if you get no spark at either end and then get a spark when you ground one plug lead.
Click to expand...
That's interesting. I don't have a way to check both sides at once. But when I checked each one one at a time they both only fired every once and a while.
 
troy-built said:
That's interesting. I don't have a way to check both sides at once. But when I checked each one one at a time they both only fired every once and a while.
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Should fire every stroke
Get a white paint pen and mark the flywheel at TDC
Every time the white mark goes past the plug should fire
If not then the coil is toast
These coils are very sensitive to both the spark plug and the plug gap .
What plugs are you using ?
Very common for the monkey behind the parts counter to grab the wrong bannana when you say Briggs plug .
 
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