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[Sir Tigger KC]

Didn't you know that petrol mowers hibernate in the winter M'lud? 

You need an electric one! 

Had one....with two fifty metre leads. Still not enough. Petrol is the answer, especially for cars.

Obviously not or you'd have been out mowing your lawn rather than asking us why your mower won't start! 

[Field Marshal Dr. Opti]

How old is the fuel?


As it's only a mower don't answer that, just dump whatever fuel is in the tank and flush the carb with fresh petrol.


While you have the plug out(that's how you know it has a spark), put your finger over the hole and check for compression.

Are you thinking a sticking valve may be a possibility, Nick?

Back in the seventies my highly tuned 2 stroke bikes would lose compression with holed pistons......but I hardly think that is likely on a plodding 4 stroke mower.

[Nick W]

How old is the fuel?


As it's only a mower don't answer that, just dump whatever fuel is in the tank and flush the carb with fresh petrol.


While you have the plug out(that's how you know it has a spark), put your finger over the hole and check for compression.

Are you thinking a sticking valve may be a possibility, Nick?

Back in the seventies my highly tuned 2 stroke bikes would lose compression with holed pistons......but I hardly think that is likely on a plodding 4 stroke mower.

More like sticky rings.


But I'm sure you know more about those than I do

[ronnyd]

I thought they would be digging up their carrots & sprouts ready for Christmas. 

Maybe next week, too much excitement in one day isn't good for the old fella.😁

I'm decades younger than you and younger than the Irish fella.

In actual years, maybe, but I was talking about brain age. You need to stimulate the grey matter, not be reading last years news. 😆

No maybe about it. I believe you are a couple of years older than Ronny.

He must be bloody old then>

[Keith ABS]

 Its the winter hibernation time for mowers.
Mine would not start either a fortnight ago

[Field Marshal Dr. Opti]

How old is the fuel?


As it's only a mower don't answer that, just dump whatever fuel is in the tank and flush the carb with fresh petrol.


While you have the plug out(that's how you know it has a spark), put your finger over the hole and check for compression.

Are you thinking a sticking valve may be a possibility, Nick?

Back in the seventies my highly tuned 2 stroke bikes would lose compression with holed pistons......but I hardly think that is likely on a plodding 4 stroke mower.

More like sticky rings.


But I'm sure you know more about those than I do

Yes...rings certainly need lubrication to encourage smooth up and down movement of a large piston.

[STEMO]

How old is the fuel?


As it's only a mower don't answer that, just dump whatever fuel is in the tank and flush the carb with fresh petrol.


While you have the plug out(that's how you know it has a spark), put your finger over the hole and check for compression.

Are you thinking a sticking valve may be a possibility, Nick?

Back in the seventies my highly tuned 2 stroke bikes would lose compression with holed pistons......but I hardly think that is likely on a plodding 4 stroke mower.

More like sticky rings.


But I'm sure you know more about those than I do

Yes...rings certainly need lubrication to encourage smooth up and down movement of a large piston.

Eeeeeeee....yer dirty bastid 🤪

[Field Marshal Dr. Opti]

I thought they would be digging up their carrots & sprouts ready for Christmas. 

Maybe next week, too much excitement in one day isn't good for the old fella.😁

I'm decades younger than you and younger than the Irish fella.

In actual years, maybe, but I was talking about brain age. You need to stimulate the grey matter, not be reading last years news. 😆

No maybe about it. I believe you are a couple of years older than Ronny.

He must be bloody old then>

He is of biblical age. His lad is just waiting for the 'inevitable'. 

[Field Marshal Dr. Opti]

How old is the fuel?


As it's only a mower don't answer that, just dump whatever fuel is in the tank and flush the carb with fresh petrol.


While you have the plug out(that's how you know it has a spark), put your finger over the hole and check for compression.

Are you thinking a sticking valve may be a possibility, Nick?

Back in the seventies my highly tuned 2 stroke bikes would lose compression with holed pistons......but I hardly think that is likely on a plodding 4 stroke mower.

More like sticky rings.


But I'm sure you know more about those than I do

Yes...rings certainly need lubrication to encourage smooth up and down movement of a large piston.

Eeeeeeee....yer dirty bastid 🤪

140cc......almost 3 mopeds.

[Field Marshal Dr. Opti]

How old is the fuel?


As it's only a mower don't answer that, just dump whatever fuel is in the tank and flush the carb with fresh petrol.


While you have the plug out(that's how you know it has a spark), put your finger over the hole and check for compression.

Are you thinking a sticking valve may be a possibility, Nick?

Back in the seventies my highly tuned 2 stroke bikes would lose compression with holed pistons......but I hardly think that is likely on a plodding 4 stroke mower.

More like sticky rings.


But I'm sure you know more about those than I do

With regard to compression......

I have used my thumb as a 'butt plug' and can confirm there is plenty.

[Field Marshal Dr. Opti]

I'm wondering.

Petrol in tank which is reaching the carb, which 'appears' to make the plug wet. Spark is 'reasonable but not that 'fat and juicy'

Is it possible the integrated HT lead/coil is not quite good enough, and the spark from the plug is being snuffed out under compression before it has the chance to ignite the petrol/air mix?

[Nick W]

It's possible, but proving it won't be easy.
I'd still be looking at the carb before going any further, and then move onto the timing.

[Field Marshal Dr. Opti]

It's possible, but proving it won't be easy.
I'd still be looking at the carb before going any further, and then move onto the timing.

Thanks, Nick. I'll take the carb apart and see if any filters or jets within it are blocked. I did think the plug would be wetter than it is considering how many times I've tried to get the bastard started.

The carb is made of plastic.

It looks as though I can buy the HT/coil combo from Ebay for about £15. The mower is only 3 years old.

[dave the builder]

could well be the diaphragm that pumps the fuel if it's B&S junk

[YZ250]

They can be temperamental bastids when not used regularly. I doubt it's timing or HT related as it was running when you switched it off. Check that mice haven't nibbled the fuel line, plunger bulb or HT lead. Timing is only usually an issue if you've hit something hard with the blade, which sheers the woodruff key, and then the crankshaft slips out of place to the timing plate.
Normally a good spin with the starter rope is enough to get them going but carb issues are generally the culprit. You also have to be careful which way you tip a petrol mower as the oil will find every little hole in the engine. My wife tipped our Toro on its front to free the blade from clogged grass and then wondered why it wouldn't start again. I cleaned the carb and tried starting it until my shoulder gave up. Luckily, when you remove the top cover of a Toro you can see the crank nut that the rope coil sits on. A socket on an adapted extension, fitted in a decent drill, will start it in seconds if all is ok. Dangerous but effective.
Carbs don't wear out as they are such low pressure fuel flow on these, but many change them as they think it's the cure. I'm yet to replace one, even on mowers over thirty years old. What engine is it, Briggs and Stratton ??  if so, what series is it (Usually on the engine cover) as I need to know what carb it has on it. Some are a resonating fuel diaphragm, and some have a proper bowl. The resonating diaphragm can be manipulated by hand to give it movement, as they go a bit stiff when not used regularly.
Are you using the rope pull in the rope guide on the handle. If so, remove the rope from the handle guide and pull from the engine as you get more revolutions per pull.