Puzzling Lawm Mower Problem

I have a TORO "Recycler" Electric Start Mower, model 20018. The mower starts fine - with the key - when cold. The Mower runs fine either hot or cold.

After its run for a short time, it will no longer start with the key. The battery is fine and the starter motor rotates the flywheel , but its as if there is either no Gas or No Spark.

Here's the puzzling fix. If I pull the cord, slowly and easily, without even trying to start it, it will then start with the key.

If its shut off, it will again be necessary to give the cord a short and easy pull, before it will again start with the key.

I have replaced the plug, the coil assbly, and have checked the kill switch.

Anyone have an idea as to what the problem may be ??

Reply to
mandhat
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Hi, What if you remove fuel tank cap when trying start? Or spray cold water around gas lines, tank and carb?

Reply to
Tony Hwang

Hi, What if you remove fuel tank cap when trying to start? Or spray cold water around gas lines, tank and carb?

Reply to
Tony Hwang

Please correct me if I=92m wrong but I don=92t see a fuel filter in the par= ts list. Does it have a fuel filter?

Reply to
recyclebinned

First guess--vapor lock.

Think Tony's thinking same thing.

If you let it cool w/o doing anything, it will then start just fine again, right?

Look into adding some reflective tape or a heat shield around the fuel line between hot engine parts and the line...

Reply to
dpb

Thanks for your reply. Removing the gas cap didn't help. I haven't tried cooling the area you mentioned.

I can try that but not sure its an issue as the engine starts with the key immediately after pulling once on the cord.

Pulling once on the cord before turning the key is doing something to resolve the issue.

Reply to
mandhat

Does it have a fuel filter?

Not that I'm aware of.

Reply to
mandhat

I haven't tried just letting it cool or spraying the areas mentioned. I'll do that tomorrow and let you know.

What I can't understand is what pulling the cord (without starting) does that the starter motor doesn't ?? The only difference I can see is that the cord revs the flywheel from the top and the starter motor revs it from the flywheel teeth below - both in the same clockwise direction.

I can let that starter motor run for at least 5 seconds and it won't start, and repeat that many times to no avail, but when I just give one pull on the cord (without starting) the electric start will then work after only one or two revs.

Reply to
mandhat

Speed?

Reply to
Dean Hoffman

On 6/17/2012 2:32 PM, snipped-for-privacy@carploin.com wrote: ...

My bet is the slow manual pull doesn't cause accelerator pump to actuate and lets vapor pressure drop whereas the high-speed (relatively) cranking doesn't (enough, anyway).

The cooling test will be pretty conclusive whether the supposition is right or not.

There's always a possibility there's some other heat-related issue but that it acts as it does and you've replaced parts that are most likely it seems a lower probability at least until the alternative is eliminated from consideration.

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Reply to
dpb

check for spark at plug. pll plug wire off in broke condition and see if another plug has a spark.

if it sparks good in broke condition add some gas to the plug hole and try starting mower.

theres just 3 possibilties, no spark, no compression, or no fuel.

along with a 4th possible.

the starter is going bad and cranks the engine too slow, but pulling cord frees things up a bit allowing it to start with key.

if the battery is 12 volts try starting it in the broke condition with a charger attached

Reply to
bob haller

lter in the parts list. Does it have a fuel filter?

Especially since your lawnmower does not have a fuel filter, I suspect that= the carburetor/metering device/fuel discharge orifice is partially blocked= . That would be the next place that the gasoline goes to after leaving the = fuel tank but before reaching the combustion chamber where the spark plug i= s. My guess is that when the lawn mower is running there is enough pressure= to keep the fuel flowing as when you pull the cord slowly you are causing = enough suction to overcome the blockage. You will need to open the location= where the fuel metering orifice is and clear the blockage. It would also b= e a good idea to install a fuel filter=20

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to the fuel line. Even if this is not the reason why you are having the pro= blem, I guarantee that without a fuel filter you will have this problem in = the future.=20

Reply to
recyclebinned

Let me make sure I understand this, if instead of pulling easily on the cord you simply try and use the electric start, which also turns the engine in the same direction, that won't make it start....

Reply to
Ashton Crusher

Let me try to clarify - hopefully I will do a better job this time.

Using the cord would eventually start the mower when hot, but my wife uses the mower and does not want to pull the cord to make it run. That's why I bought the electric start.

As a workaround, she will pull the cord gently if that will allow her to start it with the key. According to her, pulling the cord in that manner requires no effort, where trying to pull it to make it start does, especially if she has to pull it a few times. I am not about to argue, since she does cut the lawn.

In the morning, with a cold start and fully charged battery, and after pressing the primer bulb - slowly - three times, the mower starts immediately with the key.

I did a test this morn - per tony & dpb's suggestions. After it is run a short time - for about a minute - and then stopped for about a minute, it will not start with the key (it revs but does not start). If the cord is pulled once, it will then start with the key. If its left for about 15 minutes, and then primed, it will start with the key again (without pulling the cord).

The following was done: Cleaned Carburetor, Replaced Carb Bowl Gasket and Washer, Replaced Carb Seat, Needle and checked & adjusted Float, Replaced Magneto Assbly (Tecumseh "Lamination") & Adjusted Gap, Repalced Spark Plug, Cleaned Engine Fins & Externals thoroughly, Dumped Gas, Cleaned Tank & added new Gas, Changed Oil.

After all of the above, the engine ran much better (no missing), but did not change the original Hot Start w/Key problem.

Reply to
mandhat

Not sure that's the case. When you pull very slowly, there is no resistanc= e. You are clearly not pulling against compression. I'm not sure what the= mechanism is, but some speed is required to lock up and spin the engine. = Is there a centrifugal clutch, maybe? =20

I know that doesn't help with the diagnosis, but it might spell the differe= nce between the rope pull and the key start.

Reply to
TimR

On 6/18/2012 11:00 AM, snipped-for-privacy@carploin.com wrote: ...

I don't see the real suggested test(s)... :)

a) after hot and doesn't start, before the pull test cool down the carb area (spray w/ hose will work) and then try the starter, or

b) let it really cool off (by itself it'll take perhaps as long as an hour if really warm) w/o doing anything else.

I forget about the stupid prime buttons--nothing I have is that new if that small :)

Is it being used when trying to start hot? If so, possibly it's flooding it out instead of a vapor lock.

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Reply to
dpb

When pull very slowly valves don't close rapidly enough to build much compression so don't notice it (much). That also gives somewhere for the vapor to go if it is vapor lock.

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Reply to
dpb

I don't THINK you have a real case of vapour lock, since there is no fuel pump. Fuel boiling out of the carb and "dry flooding" the engine is a possibility (mixture too rich to light) and turning the engine through slowly by hand COULD be moving enough air through without drawing more fuel like it would with a fast enough crank to try to start the engine.

Pulling the starter rope turns a "sprague clutch" that catches the flywheel (using different mechanisms on different engine - ball bearings in a race on some old Briggs engines, steel tabs on some others - and likely several I've either forgotten or never seen) which turns the motor. MOST small engines in the last 40 years have some sort od "compession release" which either holds a valve open or closed below a certain speed to allow the engine to be spun up to starting speed easily. When up to speed the compression release goes off, allowing full compression, which starts the engine.

The ONLY thing I can see hand cranking the engine slowly acvcomplishing is diluting the charge in the intake and cyl by moving air through the system.

Reply to
clare

One other thing to try, if you are reasonably handy, is to hold the throttle butterfly wide open when cranking with the starter to see if it starts then. Be ready to release control to the governor as soon as it starts. If this s tarts the engine, it IS flooding. Perculation of the gas in the carb will do this - known as a "dry flood" - and a leaky float valve or excessively high float level can cause a "wet flood" - which is harder to clear and will give you a wet spark plug if you pull it to check when it is in "no start mode"

Reply to
clare

On 6/18/2012 5:23 PM, snipped-for-privacy@snyder.on.ca wrote: ...

...

Well, there is a fuel pump, it's the diaphragm/spring in the carb...

One I've spent today playing with...392/432 and 390 w/ pinhole in diaphragm. That way it doesn't do too good... :)

But yes, if it is as I've suggested it is as you describe that's going on--and the name seems as good as any for discussion purposes here.

I've seen it on one B&S and while it didn't have electric start to have a symptom just as the OP's, cooling it down would work which is how I came up w/ the foil and a heat shield idea that (pretty much) solved it.

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Reply to
dpb

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