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Petrol Lawnmower

Hi guys, hoping someone can help me here.

We have a year old petrol lawnmower, it worked fine last year and used it probably a dozen times, then it sat in the shed over the winter and now it comes out to play as the sunshine and spring arrive.  However, it won't run :(  I've emptied the fuel tank and put brand new fuel into the tank. It has oil in there and everything is as it was last year. 

It's a Tesco lawnmower and it's very easy to operate.  You prime it a couple of times with this bulb like thing which draws the fuel into the carburettor I presume and once it starts it manages the fuel flow from there.  This is great and we can get it to start but once the fuel that's primed runs out (almost instantly) it won't continue to run...

The spark plug is clean however that wouldn't be the cause as it always starts upon priming and then engine sounds fine, it's almost as if the fuel is not being drawn into it after it starts.

Any suggestions greatly appreciated.


  • TopbirdTopbird Posts: 8,192

    My Honda petrol usually starts easily - but first outing of the year it's usually a pig!

    Usual suspects are - stale fuel, condensation in the fuel tank, gungy spark plug - but it sounds as if you've looked at all those. Is the fuel brand new from the garage (rather than what you've stored yourself over winter). If not I'd try that.

    I would check the air filter in case it's blocked - but I bet it's not.

    If all else fails I would leave it in the sun to warm up a bit. Don't know why but this works for mineimage If it has a choke on it try various settings and then leave it for half an hour and come back to it again. 

    Just a last thought - is the fuel tank tap turned on? If you've had it serviced they usually turn it off for safety when transporting.

    Failing that you could take it back to Tesco. If it's a year old it should still be under warranty (or only just out of it) - and they might swap it.

    Heaven is ... sitting in the garden with a G&T and a cat while watching the sun go down
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  • Tony121Tony121 Posts: 2

    Hi there,

    Thanks for that, yup, tried it with the cap loose.  We also primed the fuel whilst it was running and it stayed running for longer but I think it flooded it as you could hear it gradually splutter, due to overriding the mixture control I guess...  It's seeming that something is stuck in the jet or something, a bit of dirt perhaps?

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  • ColinAColinA Posts: 382

    It sounds like the main jet in the carb is blocked. the carburettor will need removing and thoroughly cleaning out using compressed air to clear the jets,Also the fuel tank will need cleaning out as thats the only way dirt can ingress into the carburrettor

    Its no use taking it back to tesco as this is not a warranty fault


  • Pete.8Pete.8 Posts: 10,915

    I very much agree with ColinA's diagnosis. There's some fuel getting through, but not enough fuel to keep the engine running. So almost certainly a bit of 'stuff' slowing the flow. A good clean-up should sort it

    Billericay - Essex

    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • KT53KT53 Posts: 8,462

    My Honda refused to run at anything faster than tickover last year, and obviously then stalled when I tried to cut with it.  That was actually a carburettor fault and was changed under warranty.  I'm not expert but it does sound like a problem linked to the carburettor.  Unlikely to be a fuel flow from the tank problem if it primes OK.

  • TopsoiledTopsoiled Posts: 113

    One thing to check, look for a thin/springs wire coming off the carburettor which may have become detached, very easy to re-attach. It's out 2-3 inches long, very thin.

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