Lawnmower wont start

[landuse]

Hi guys, maybe you can help me out here.

I have a 2 stroke EC10 lawnmower that is quite old, but has been going great forever. I have had the normal ups and downs, but there has never been any major mechanical failures.

So last week my gardener used the mower to cut the grass, and everything worked fine. He did however run out of petrol mix just as he finished.

This weekend, he tries to start it and nothing happens. We have filled up with petrol mix again, so that isn't the problem. I check that petrol is getting to the carb (and it is, no obstructions in fuel line). I then decide to take the plug out after some vigorous pulling of the starter cord, and I see that the plug is bone dry. There is no fuel getting to the plug at all, so I assume that there is a blockage in the carb somewhere. I also check for spark and it does have spark.

I rip the carb off, give it a good clean and put it back on. It still doesn't want to start after numerous pulls of the starter. The plug is now however getting wet, so fuel is getting through the carb to the plug.

I tried another spark plug, but it wasn't the right type cos it was all I had. Still nothing

I know that I have to get a correct plug and check it then, but what else do you guys think the problem might be. It has spark and fuel. The air filter is also clean.

Can you guys give me any more ideas. I will be able to hunt lions in my grass if I don't get it cut soon.

 

[jman231994]

Hows the compression?

 

[jman231994]

And is there any chance you could take the cowling off it? It looks suprisingly like fallen leopards mystery engine

 

[landuse]

Compression is fine. That shouldn't be a problem. These engines were made by Robin Subaru

 

[Russ2251]

Is this reed or piston ported induction?
I assume the latter.
Check for coked up exhaust port.
Check key for shear.

 

[landuse]

Is this reed or piston ported induction?
I assume the latter.
Check for coked up exhaust port.
Check key for shear.

It is piston ported. I will have to check the exhaust port. I don't think the exhaust have ever been removed before. I will have to take it off and have a look.

I have also not looked for a sheared flywheel key. I was hoping to nail the problem down before I had to tear down to that extent. I will check that too.

 

[Doc Sprocket]

Perhaps it flooded in latest attempt? Clean/dry plug and take another stab at it. Maybe yank kill wire off long enough to test.

Even the wrong plug (if good) should net a result.

Did the gardener report any strange behavior at end of last run?

 

[landuse]

Perhaps it flooded in latest attempt? Clean/dry plug and take another stab at it.

Thanks Toystory. I did clean and dry the plug a few times, and it didn't seem to help any.

Maybe yank kill wire off long enough to test.

If I have confirmed that I am getting a spark (with the kill still connected), would it make a difference disconnecting it? Would it maybe make it spark stronger?

Did the gardener report any strange behavior at end of last run?

He did not say anything happened, but maybe he is too scared to tell me he did something to it.

And is there any chance you could take the cowling off it? It looks suprisingly like fallen leopards mystery engine

I will take a pic when I remove the flywheel

 

[Doc Sprocket]

Generally, there's no "partially killed", so to speak. When the kill circuit is complete, you have no spark. I just usually eliminate it early in the troubleshooting.

I assume you have tried injecting either mix or starting fluid directly into the combustion chamber?

Have there been ANY signs of life? A single fire? Any smoke (not to be confused with fuel vapour) from the exhaust?

 

[landuse]

I assume you have tried injecting either mix or starting fluid directly into the combustion chamber?

I have tried spraying some engine starting spray into the plug hole and then putting the plug back in. There has been absolutely no change.

Have there been ANY signs of life? A single fire? Any smoke (not to be confused with fuel vapour) from the exhaust?

It has not coughed, smoked, or anything else. Pulling the flywheel of to check the key is a last resort for me at the moment. I have to go buy a plug first to eliminate that, but as you say, a plug, whether it is the wrong one, should give some sort of result.

 

[B man]

Does it have a oil sensor on it anywhere?

Are you sure you got spark? cause if you had spark and starting fluid then it should have done something atleast.

the only other thing i can think of is low compression. but even then it should atleast try.

Did he hit anything with the blade? that could cause the key to shear.

 

[landuse]

Does it have a oil sensor on it anywhere?

Are you sure you got spark? cause if you had spark and starting fluid then it should have done something atleast.

the only other thing i can think of is low compression. but even then it should at least try.

Did he hit anything with the blade? that could cause the key to shear.

Thanks Bman. I don't have a low oil sensor at all. It is a 2 stroke

I worked on it a bit last night, and came to the conclusion that it is the spark that is giving me a problem. It is intermittent, and sometimes doesn't spark at all. I found that one of the wires to the kill switch was hanging by a thread, so I fixed that. It is still not really giving me spark though.

I pulled the cowling off the engine and took the flywheel off. The key is not sheared , so I can rule that out. I am not really an engine electrics whiz kid guy, so you are all going to have to help me here. I have circled the wire coming from the coil out of the engine. If I leave that unattached to anything, I should theoretically have no kill switch and the engine should spark. Is that correct??

I did notice that there was a little water under the flywheel. Would this moisture affect the coil and sparking of the engine?

I am a little confused now as to what I should do/check.

Any ideas?

PS: Sorry for the low quality pics. I forgot my camera settings were set to low quality

 

[Doc Sprocket]

Yes- I believe that's the kill wire. Make sure the insulation isn't cracked anywhere, where it can short out against any metal.

Moisture in electronics is generally not ideal. It's possible...

 

[jman231994]

Thanks for the pics, nothing like hers sadly....the mystery continues.

And yea, that wire is the kill wire, when it shorts to anything it will prevent spark, as toystory said. Also make sure the spark plug lead itself isnt cracked and shorting somewhere, that would cause a weakened or lack of spark....and a good zap for whoevers using it lol

And, does it have a sump for some reason? Looks like an oil plug there...

 

[Russ2251]

And, does it have a sump for some reason? Looks like an oil plug there...

For self propel.

 

[landuse]

For self propel.

What do you mean by "self propel" Russ?

The image below is what the manual says. For the governor chamber. I am not too sure what the oil is for though

 

[Russ2251]

It also says "reduction chamber" as in gear reduction.
This should clear things up:
self propelled

 

[machinist@large]

:ninja: What kind of terrain do you live in that your PUSH MOWER (!?!) needs a remote snorkel?

 

[B man]

Well id bet money on the coil. it is a good possibility with that things age. I heard you can try baking some coils (might just be lawnboy coils only though) to bring them back to life.

 

[landuse]

:ninja: What kind of terrain do you live in that your PUSH MOWER (!?!) needs a remote snorkel?

LOL. That is where the air filter usually goes. Here is a pic of what it should look like with the filter etc hooked up. You can see the filter cover and the hose going up to another air filter on the handle

Well id bet money on the coil. it is a good possibility with that things age. I heard you can try baking some coils (might just be lawnboy coils only though) to bring them back to life.

So I worked on the engine a little more last night when I got home, and I also think that it is probably the coil, or the spark plug boot. I think it is the coil though. The kill wire and spark plug wie are all in good condition with no fraying, and the kill wire was left unatached when trying to start the engine (ie. no kill switch).

I am dreading the cost of a new coil. Things aren't cheap here, and I know it is going to cost me. I am going to get some quotes, and I will let you guys know what a new coil costs here.

Has anyone got any other ideas?

I wanted to ask you guys who know. How do you set the gap between the magneto and whe flywheel on this engine when you have to remove the flywheel to get to it? The coil is under the flywheel, not beside it like on horizontal type engines

It also says "reduction chamber" as in gear reduction.
This should clear things up:
self propelled

I don't think there is any gear reduction on this engine. It was made as a push mower, and there is no reduction gears/box on the mower. That is why I assumed it was for the governor that is situated next to the oil reservoir. I know what self propelled means, I just don't see how it applies to my engine??