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.Mod 20436
ser 3907024. B&S motor.5.5 Thanks for the previous help on my "Which spark plug " post.This new to me Toro seems to only want to run for
5-10 mins and cuts off.I replaced the air filter,spark plug,changed oil and dropped the carb bowl and cleaned the lateral jet hole.
carb bowl was cleaner than I expected.Actually very clean.Lateral hole had a tiny crud in it .top hole does not seem like an actual hole.
Seems more like a fitting?? Could not poke anything thru it.Kinda puzzled so I put the old plug back in and it is doing the same.
Made a fuel cocktail with Berrymans Chemtool,Chevro techron,and Seafoam and let it run through the system with gas for cleaning.
Kinda puzzled.BTW,it does not immediately restart.5 mins or so then it starts on choke.Everything connected to carb/throttle seems connected
and moving with throttle handle accordingly.Hmmmmmm Charlie

Get yourself a red inline spark tester
Fit it so you can see it then go mow
If the red globe stays red and flashes as the engine slows down to a stop you have a fuel problem
If the lap goes out well before the engine stops you have an ignition problem .
You have to work out which system is failing or you will just e running around in circles chasing your tail .

Thanks,is the spark tester a Harbor freight item?

BTW I removed the bowl several times after cutting out and there was same small amount of fuel in bowl each time.

Yes they do, just checked, $4.00.

guess I will do that.Is there a coil on these motors?

Oregon P/N is 42-031 but every other aftermarket parts supplier does one
They look like the image below and can be left on engines forever if you like
I regularly loose them only to find on ( or 2 ) on a customers engine I worked on at their house years ago.
They actually flash every time the plug gets a power pulse , but our eyes will see it as a constant red glow at most speeds over 2000 rpm
Now if the plug is bad & the spark is tracking down the sides of the plug , it will still glow / flash so it does not rule out a bad plug
It just allows you to work out where you should be looking
Probably the most used tool in my diagnostic tool kit .

bertsmobile1 said:

Get yourself a red inline spark tester
Fit it so you can see it then go mow
If the red globe stays red and flashes as the engine slows down to a stop you have a fuel problem
If the lap goes out well before the engine stops you have an ignition problem .
You have to work out which system is failing or you will just e running around in circles chasing your tail .

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Thanks for the perfect explanation!! I was always under the impression that there is either spark or no spark.
Interesting...I once had a 68 Corvette.I was told that the coil was getting overheated as I drove and it would
shut the 328 down.Bought an Accel super coil and problem solved.I think it was $39 back then...lol Charlie

Modern fuel is not PETROL which is why it is called fuel & not petrol.
Petrol is not conductive at cylinder compressions
Fuel is conductive at cylinder pressures
So a damp plug will just run the spark down the side rather than jump the gap.
The old trick for emergency fis of a fouled plug was to hold the plug lead 1/2" to 1" off the end of the plug
The voltage supplied to the plug is onto 0 or 30,000.
It starts at 0 then rises to 30,000 ( very quickly ) .
When you hold the plug lead off the end of the plug , nothing can happen till the voltage gets high enough to jump the gap at the lead so when that voltage gets to the plug it is high enough to jump the gap .
As you can see I have driven a lot of vehicles rescued from the scrap yard

So Harbor freight was out of the spark testers so it will be in next week.Started the mower today on the 3rd pull and ran it around the yard for close to half an hour without stalling.When I was done I hosed it down and started it again on 3rd pull and just let it run and it ran without stalling.Later I started it again and let it run and it shut down after 10 mins.Kinda unpredictable .Will ck the spark next week.Charlie

1) sounds really like a chaffed wire, either the spark plug or magneto kill .
2) please refrain from hosing down the mower,particularly if it is hot
Blow it down with compressed air ( if you have it ) or a leaf blower

If you must hose the mower then let it cool down for 1/2 hour first .

I believe you have a fuel starvation problem that may be cured by removing float bowl and carefully pulling out the pin that holds the float. The needle will come down with it. Open fuel valve and you should get good continuous flow. Reinstall and try it. If it begins to slow down after running, remove the fuel cap quickly in case Vent was plugged. If your unit has a fuel pump, crank it a few times with float bowl off. Fuel should come out.

So I put old spark plug back in and supercharged the fuel with Berrymens chemtool,Seafoam and Chevron tychron ,all added to gas.Nice
happy hour cocktail for the Toro .No stalling at all after using it for hours this week.All good now!! I just wish it started earlier than 3rd or 4th pull.Gonna pull spark plug and clean combustion chamber with Seafoam.Charlie

crazy charlie said:

So Harbor freight was out of the spark testers so it will be in next week.Started the mower today on the 3rd pull and ran it around the yard for close to half an hour without stalling.When I was done I hosed it down and started it again on 3rd pull and just let it run and it ran without stalling.Later I started it again and let it run and it shut down after 10 mins.Kinda unpredictable .Will ck the spark next week.Charlie

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From my experience, I suspect that you have a failing coil. When they start to fail they will work when cold but as they heat up, they fail. If you get a spark tester you will be able to confirm that it’s the coil. Or, after the engine quits you can spray starter fluid through the carb and try to start. If it starts, you know it is not the sparkplug/coil, and you have a fuel problem. If it doesn’t start, you have a bad coil or plug, most likely a bad coil.

crazy charlie said:

So I put old spark plug back in and supercharged the fuel with Berrymens chemtool,Seafoam and Chevron tychron ,all added to gas.Nice
happy hour cocktail for the Toro .No stalling at all after using it for hours this week.All good now!! I just wish it started earlier than 3rd or 4th pull.Gonna pull spark plug and clean combustion chamber with Seafoam.Charlie

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don't loosen up the head gasket doing that.