Advice for non starting mower

[ipbr21054]

I was given this mower tonight as the owner couldnt start it.
Same with me as i also cant start it.

Ive done the following & still wont start.
Sometimes if i squirt some carb cleaner into the carb when filter is removed i now & then get a little backfire & sometimes a puff of white smoke out the exhaust but other than that nothing.

Drained carb & fuel tank & used new fuel.
Removed air filter.
Cleaned carb & jets all clear / not clogged etc.
Changed spark plug & also tried other 2 that i have here.
Used plug tester between plug / plug cap & i can see a spark easy.
Pressing red primer bulb & looking through carb i see fuel squirt up no problem.
Squirted some carb cleaner into plug hole as opposed through air filter to try.
Disconnected kill switch wire.

 

[ipbr21054]

One thing to add to the above.
All kill switches I’ve seen are say about 8mm high with a metal arm that comes of it which when the bar is operated you hear the click click of the switch contacts.

This mower however kill switch is literally say 3mm high. It looks like a flat piece of material which has the metal arm coming off it for which touches the connection from the bar lever.
I don’t see how a switch can even be in something this thick 3mm ?
I did unto the two screws that hold this in place & just let it hang around whilst I tried to start the mower.

 

[Burnerman]

You are now pretty experienced with these things!
One symptom of the odd firing but not running is a sheared flywheel key.....a spark still occurs but its just not at the right time so you get the odd backfire.
Removing the flywheel is no big deal.....once the cooling cowl is off and the centre nut slackened I tap a couple of wedges under the flywheel and strike the flywheel nut with a hammer. The jolt sets the flywheel free sharpish.
John

 

[ipbr21054]

Ahh so timing is out maybe.
So after I remove the pull cord black cover I then need to take off the metal coiling underneath.
Then one end of the crank will be exposed ?

 

[Burnerman]

Yes, you’ll see the flywheel in all its glory, and the crankshaft tapered end once the flywheel is off.
There’s nothing below the flywheel but grass and dust!
John

 

[johnny2007]

Remove spark plug, squirt 1ml of ethanol in the combustion chamber, put back the spark plug and try again.

 

[ipbr21054]

Johnny I did that but with carb cleaner but nothing.

 

[Nige F]

Looks like a Chinese one to me , so I wouldn't be surprised if the woodluff key holding the flywheel had broken - like Burnerman said.

 

[ipbr21054]

Ive got this far at present & i know that i need to pop this flywheel off but just showing you anyway just incase you see next line of text.

Please look & advise of the cut out switch.
There is a bent piece of sprung steel but where i assume the switch contacts would be enclosed in a box of some sort there is just a thin piece of plastic / metal maybe 2mm thick.
Surely this isnt correct ??

 

[ipbr21054]

Ive found the model number for the mower now & took a quick look on ebay.
This is the cut off switch as shown in photos.
So mine is obviously broken going by whats left of it.
Now to see if it starts with the wires connected or apart.

I see this wire from the switch goes around to the coil.
So my question is can i just remove the thin wire at the coil ?
Im not sure in the wires joined or apart that stop the engine ?

Please advise

 

[ipbr21054]

Here is the switch.
Normally i would expect the screws to be diagonal but these are inline.
There is only 1 wire.
One end is a spring piece of steel which in touched by the cable once bar is operated.
2 screws secure this in place.
The other end has a spade terminal & connects to the coil.

Using a multimeter i have continuity from spring steel to spade connection.
So as it is does the move see a spark or not ?

 

[ipbr21054]

Flywheel is off & woodruff key is in place & not broken.
Ive removed then replaced it & refiteed the flywheel.
Spinning the flywheel by hand i can see the top of the crank turning at the same time.

With that kill switch wire removed all together & trying to start i still get some popping noise

 

[Burnerman]

I’m not familiar with that micro switch kill switch, but if you disconnect the black wire and prevent it from touching any metalwork I’d expect a strong spark.
John

 

[Mr Chibs]

I have this mower, and it's a pain in the bum to start.

However, I changed the gasket... well made one from gasket paper.

It's still not the easiest to start, but after 7 primes of the carb, a pull then 7 more primes and final pull its starts... regularly...
I was given this, so I'm putting up with it for now.

 

[ipbr21054]

Did as Mr Chibs advised but still no joy.

With the kill switch wire removed i see a nice spark

Ive removed the carb again & cleaned it again.
Also removed jet, needle etc & checked / clean.
However this should be bypassed by me squirting carb cleaner through the carb port & straight into the plug hole.

But still no joy in respect of starting