Lawnmower cutting out/not starting

krlyr

I was given a Tesco petrol lawnmower a couple of years ago - barely used, but no manual. The last couple of uses, it was cutting out when it reached a thick/long patch of grass, but would OK on the rest of the lawn once restarted. However, last use it conked out and just wouldn't start again.

Bit clueless about mowers, could this be down to it being out of oil? I've never actually added any, it's not had a whole lot of use but it has been used for the last 2 years so guessing it may need some. Reluctant to spend out £8 for a bottle of oil though and find out the lawnmower is just dead - moving to a house with a smaller garden soon so I'm likely to just buy a little electric mower so wouldn't need the oil again!

Davesnave

Why are you 'guessing' that it may need oil? Either it does, or it doesn't, so if you can't be bothered to look, no one here can advise!

But the chances are it's been sitting in the shed from autumn until now, so the petrol will be stale and it won't start without fresh fuel, never mind the chance that the carburettor jet may be blocked,or the spark plug gap covered in black stuff, which are 2 other reasons for not starting.

All petrol engined garden tools need maintenance and the occasional service, so if a bottle of oil is too much to invest, you're better cutting your losses and just getting something that plugs in. Don't forget the RCD.

Ebe_Scrooge

As per the above, stale fuel and a gummed-up carb are very common problems on petrol-powered garden tools.


The oil is easy enough to check, it's just like checking the oil on your car ( it is 4-stroke, yes ??? ).


The other thing to check is the air filter - usually it's just a sponge filter that can be washed clean and replaced when dry. If the engine is struggling to breathe then this could also be a factor as to why it's struggling under load.


If you can find a model number somewhere on the mower, odds on you'll be able to find the manual online. This will hopefully show you how to clean / service the various parts of the engine, and may also give you a trouble-shooting list.


But as a start : empty out the fuel, clean the carb, clean the air filter, clean the spark plug, refill with fresh fuel, check the oil level. Odds on that'll do the trick.

krlyr

Davesnave wrote: »

Why are you 'guessing' that it may need oil? Either it does, or it doesn't, so if you can't be bothered to look, no one here can advise!

But the chances are it's been sitting in the shed from autumn until now, so the petrol will be stale and it won't start without fresh fuel, never mind the chance that the carburettor jet may be blocked,or the spark plug gap covered in black stuff, which are 2 other reasons for not starting.

All petrol engined garden tools need maintenance and the occasional service, so if a bottle of oil is too much to invest, you're better cutting your losses and just getting something that plugs in. Don't forget the RCD.

Because I'm currently sat at work, with no access to the lawnmower, and wondering if I need to pop somewhere on my way home for oil or if I have a dead lawnmower that I don't need a bottle of oil for. The whole point of this forum is about saving money - I'm happy to invest in a working lawnmower but not throw money away over a broken one.

And, as my post clearly says, I've not got a clue about lawnmowers so I thought a "Yes, lack of oil could cause it to not start" or a "No, lack of oil might cause X, Y and Z but lawnmower should at least start up" from someone who knows these things would be a big help towards figuring it out.

Ebe_Scrooge wrote: »

As per the above, stale fuel and a gummed-up carb are very common problems on petrol-powered garden tools.


The oil is easy enough to check, it's just like checking the oil on your car ( it is 4-stroke, yes ??? ).


The other thing to check is the air filter - usually it's just a sponge filter that can be washed clean and replaced when dry. If the engine is struggling to breathe then this could also be a factor as to why it's struggling under load.


If you can find a model number somewhere on the mower, odds on you'll be able to find the manual online. This will hopefully show you how to clean / service the various parts of the engine, and may also give you a trouble-shooting list.


But as a start : empty out the fuel, clean the carb, clean the air filter, clean the spark plug, refill with fresh fuel, check the oil level. Odds on that'll do the trick.

Thanks. Yes, found a model that looks the same online and it says it's a 4-stroke. No manual to know what bits I need to take off to get to what though, but will look for a model number when I get home and have a Google. Good to know about the air filter, gives me another thing to try. Fuel in it is fresh, so one thing off the tick list.

Davesnave

I think my first post implies that you don't really need to worry about oil until other things have been checked. Once it's going, oil is very useful though!

Ebe has added another possible reason for non-starting that I forgot.

Anyway, you sound much more 'up for it' now. If you can't find the right model, many mowers share the same engine/carb set up, so a similar one's manual may help.

Mr.Generous

Another vote for fuel, old petrol is deadly to mowers, it loses the octane rating when stored and as it gets older gives less and less power until a warm engine will refuse to start.

Throw away the fuel in the tank - burn it or use as weedkiller - a few drops on the leaves kills anything. Fresh fuel. If it doesn't start then new spark plug - probably a J8 - and it should run.

But as everyone has said FUEL first.

Browntoa

Sounds like the rubber membrane that acts as the petrol pump that sits under the fuel tank has perished , sounds like similar symptoms to mine

The engine is often made by only 1 or 2 companies , look on the engine for the maker's name and model

A replacement membrane is normally only £4 or £5 for an original , YouTube guides will show you had to do it

Simple job , couple of bolts , lift off the petrol tank , unbolt the carb , membrane is underneath. Replace and reverse

Clean the spark plugs head with a wire brush to be sure

arbrighton

This is why you're supposed to drain fuel if not used for a while (e.g. over winter)

Our mountfield was very sputtery after the summer where the builders were here so it wasn't drained for a year or used.
OH Cleaned carb but I think eventually replaced it.

We did the oil too but it was the carb causing the sputtering

Jojo_the_Tightfisted

Any good?

http://ttselectrical.custhelp.com/ci/fattach/get/481341/1495449656/redirect/1/session/L2F2LzEvdGltZS8xNDk1NzY5NjUzL3NpZC9fcG1lenZqbg==/filename/747-2552_Tesco_135CC_Petrol_Mower.pdf

http://ttselectrical.custhelp.com/ci/fattach/get/477871/1489773426/redirect/1/filename/IM_TESCO_PLM022013_Mower_98.5ccm.pdf

This is the help site homepage

http://ttselectrical.custhelp.com/

Jojo_the_Tightfisted

You should be able to tell whether it's trying to start up - like an older car. (Don't forget that you could have flooded the thing from trying to start it).

It's a pretty simple thing, an engine - it needs air, fuel and a spark.

If it's turning over but not quite catching, check connections, then air filter. If that's clean, look at the rest, such as is it sparking at all. If you look at the spark plug, and clean it off, careful not to damage the gap with the brush - it'll be pretty clear if the plug is black carbon covered, white and pitted, brown, etc. Or cracked. If still no joy, it's probably time to check the fuel line for being clogged up with gunk along with thinks like the jets. There's probably a Haynes Manual for all this. And it'll be fun, honest. Although that might just be me.

If it made any hideous grinding noises, lack of oil would be more likely. But it will need some if you've never done it - the odds are that the person who gave it to you didn't do it either.


And you'll need some washing up liquid and granulated sugar to get the stuff off your hands afterwards. Or wear non latex gloves (fuel, mineral oil, etc dissolves latex).

If it was struggling, I'd suspect the air filter first, though. After you've established no leads have been dislodged during its stay in the shed. Or nibbled through by rodents.