Petrol mower burning oil - any tips?

mazza

Anyone able to give a bit of advice on what must be a fairly common problem with a petrol mower?

At the weekend, I tilted it forward (i.e back wheels in the air) to clear something tangled in the blade, which I now realise was a big 'no-no'.

Now when I start it up, it starts producing white smoke once warmed up - obviously burning oil which is one reason the manual says not to tilt it forward!

The manual recommends removing and cleaning the filter sponge which may have got saturated in oil - I did that, but no improvement.

It also mentions that oil can escape the 'crankcase' if the mower is tilted forward, but doesn't say how to clear this oil, so it doesn't burn! :mad:

Anyone know how to sort this or is it a job for a mower shop? Any tips?

I would just try to let it burn the oil off, but don't think its a good idea as it smokes for a short while after the engine is switched off and it also looks like the engine is getting hot at the exhaust from burning the oil.

Thanks in advance,

Maz

crosstownk

Yep - tilting the mower to any extent will cause oil to pour into the combustion chamber. You can remove the spark plug and this will give you limited access to the chamber where you can attempt to 'soak' out some of the oil. If you do this do not use a cloth that will leave bits behind in the combustion chamber.

That said, if it was my mower I'd just live with it and let it smoke - eventually all the oil will burn off.

Be sure to check your oil level as some of the oil has 'escaped the crankcase'. Do not overfill or you will be back to square one!

mazza

Thanks for the advice, crosstownk - I'll try removing spark plugs, soaking etc as you mention.

The thought did cross my mind to just let the oil burn off itself.

I wasn't sure it was a good idea as still smoked for a while after the engine was turned off and there was also a light 'TINK-ing' noise of metal expanding under heat at the exhaust.

Are you reasonably sure the mower wouldn't catch fire, overheat or damage the engine in some way if I just try to just let it burn off? Maybe it just looks more dramatic than it is, what with the smoke?

Thanks again and good luck,

Maz

crosstownk

I doubt it would catch fire. When engine oil burns it is very smokey. The fact that it starts at all indicates that there may not be too much oil in the cylinder - if there was a lot of oil the spark plug would be wet and wouldn't spark which means the engine wouldn't fire up at all.

I used to get smoke every time I started my mower due to the fact that I had to tilt it to get it into the shed. It used to burn off after a few minutes - but what a cloud of smoke!!

TheGrabbingHand

Check the oil level first and then start it and let it burn off. It will not catch fire and will be clear in about 10 mins.

Mr Magnolia

Any tips on cleaning the under-carraige round the blades etc. without tilting?

I always tilt, clean as quickly as possible then just put up with the smoke for the following 10 minutes or so, it usually stops after that. I knew that tilting caused the oil to 'spill/overflow' just can't see an alternative other than a rusty mower.

Mailman

Check oil level and top-up again.
Take off air filter off(perhaps you'll have to leave a screw in the top of the carb dependent on model of lawnmower engine.
Start engine and let smoke burn off.
Clean/Replace air filter if covered in oil. If air filter is paper then replace it as it will never let the engine breathe properly again.

the sparkplug should always point skywards if you want to inspect the underside of the lawnmower.

crosstownk

Mr Magnolia wrote:

Any tips on cleaning the under-carraige round the blades etc. without tilting?

I always tilt, clean as quickly as possible then just put up with the smoke for the following 10 minutes or so, it usually stops after that. I knew that tilting caused the oil to 'spill/overflow' just can't see an alternative other than a rusty mower.

I just lift the mower up and rest it across two high stools.

Mr Magnolia

Do they not mind you getting grass on the floor in the pub?


Thanks though, I'll try something like that so.

mazza

OK, end of story on this one for me...

I check the oil level - was fine.

Ran the mower for about 5 mins to let the oil burn off. It smoked a fair bit at first but pretty quickly started to drop off. Then ran fine just like before. Knowing that it wasn't going to damage the engine or catch fire made a big difference.

Thanks for all the tips and advice on this.

Oil's well that ends well. (Boom boom!)

Maz

Mr Magnolia

Glad it all worked out.

mazza wrote:

Oil's well that ends well. (Boom boom!)

LOL *hands mazza his coat*