Petrol lawn mower new lease of life

Yes. Might explain the *spluttering* in the OP.

I hope you changed the oil before you did anything else. If not, it isn't too late.

Andy

chuck it into your petrol can so it mixes with fresh fuel, then it's good.

Check the mower has enough oil then it's fine to try starting it. If it won't, check it has spark. If it does, the problem is most likely fuel or fuel-air mix. A little volatile fuel in the air intake often helps em get going - fuel gas of any sort works.

NT

If its been lying idle esp if 2 stroke throw the thing to the junk pile. Buy a new one. if you cann't, blame and change the govt ?!!

Car repair, usually have a barrel they put shop solvents in. They can take fuel and add it to that container for recycling. Give them a call first, to see if accepting a small amount of fuel would upset them.

Municipal hazardous waste should also accept fuel, but again, check the list of what they're taking. The last time I went to one of those, we had to wait in a line, sitting in cars, to do the dropoff. Hazardous waste is only open a few days per summer. This is intended to prevent people from using it I guess. Normally, we take paint cans there.

If you didn't mix the gas and oil, in preparation for fueling a 2-stroke, and you kept your gas and oil separate, stale gas could then just be chucked into your almost full car fuel tank. And dispose of it that way. After the oil is added, I wouldn't throw that in my car gas tank.

With a lawn mower, you run the tank dry at the end of the season. That should reduce the stale gas problem when you tank up at the beginning of the next season. For a 4-stroke riding mower, you can tip that up and change the oil at the end of season.

Paul

I add a bit of oil to my lawnmower every year, but I have never changed it in 18 years.

At around 40 hours per year usage, it hardly seems worthwhile

Its done 720 hours at 3 mph. Just over 2000 miles

You'd do the oil first?

Unless the oil is recognizably bad (water, turned to tar, not oily, ...) I'd let it run for a bit first. "Stir up the dirt and flush it out" sort of thing, change it hot and let it drip for a long time.

Not arguing, just asking.

Thomas Prufer

Ignore all the crap posted here. The volatiles have evaporated from the petrol that's all. The easy start fixes all that. The old petrol will be largely gone after the mower is run for an hour.

charles snipped-for-privacy@candehope.me.uk> posted

What is it that goes wrong with it? It doesn't happen with cars. You can leave them sitting for months and they'll start.

Why do lawn mowers suffer so much more with volatiles evaporating? Is it that the venting system on a car's fuel tank is more sophisticated and will allow air in to replace the fuel that is used, without allowing volatiles out? And why should a two-stroke outboard motor be better than a lawn mower? I'd have thought that it would have a less sophisticated vent, similar to a lawn mower's. Does the presence of the oil in the petrol help the volatiles not to evaporate as readily?

I imagine that diesel engines don't suffer problems with old fuel - as long as it isn't so cold that it has developed wax crystals, which is why the more expensive "winter diesel" (with less tendency to go waxy) is sold in the colder months. As long as the battery on my diesel car is OK, it always starts first time and is never sluggish and prone to engine-fade until it has warmed up. I drove a petrol car when I took my car in to be repaired and I'd forgotten the "joys" of an engine that lost power as I accelerated immediately after setting off when the engine was cold - and that was fuel-injected rather than carburettor-and-choke. Mind you, that car had a puny 900 3-cylinder engine that was little more than a lawn-mower engine: it emitted a rather disconcerting, head-turning barking noise whenever I tried to accelerate. But it got me around while my car was being repaired, so I can't complain.

Cars have extensive feedback systems.

The 2-stroke has nothing. It has a governor, on a gasoline engine, to control the speed for lawn mowing sessions. But it doesn't have any information to speak of, about the gas. Actually, you "give" the engine information, by adjusting the choke according to your knowledge of engine temperature.

Octane numbers represent how much compression the gasoline can handle. The higher number, the less likely it is to ignite from the pressure.

With the final, carefully calibrated product, the gasoline is composed of hundreds of different compounds ? too many to even identify and characterize, Speight said." <=== as a chemist, this statement is a joke.

"over time, "the lighter hydrocarbons start evaporating out of gasoline," Stanley told Live Science. And your car engine may not be designed to handle the resultant gasoline, if left too long."

What he means by that, is at some point, insufficient highly volatile material is there to "easily ignite" via the spark. For example, winter gasoline has additional "lights" added to it, to improve winter starting. Use summer gas in winter, and you risk a failure to start. Even if the gas was not "old", but merely poorly blended, that can cause problems.

I didn't know about this one.

"Aside from evaporation, "[gasoline] is like wine ? once you take it out of the bottle, it starts going bad. It starts oxidizing away," Stanley said.

As some of the hydrocarbons in the gasoline evaporate, other hydrocarbons react with the oxygen in the air, Speight said. The gasoline then begins to form solids called gum.

In short, you want to store your gasoline in cool, low-oxygen environments, Speight said."

On our 2-stroke lawn mower back home, the gasoline used gravity feed, and the "gas cap" had a hole in the top, to prevent restriction on gasoline flow. This should allow a good "flow" of oxygen, when the barometric pressure changes.

Cars have a more enclosed system. You'll get a Check Engine light, if the gas cap is loose - the car enforced VOC rules by checking that the fuel system is sealed (after a fashion).

Paul

I think this is nonsense. We used to run a boat with a V6 260hp engine and a 120 gallon petrol fuel tank. She would sit for 6-8 months in the off season and the petrol never caused a problem at the start of the following season.

Equally we have several pieces of petrol powered garden machinery and they never get the fuel decanted at the season end without any obvious problem

I thought that, too, when I was told by the company that service my mower which was misbehavig. So I googled.

You will be very fortunate if the fuel is the only problem.

Plenty of stuff on Google and youtube about getting a four stroke mower back up and running.

Carb cleaner and a gasket sheet is a must, if you dont want a box of bits lying around while waiting for an order.

It isn't a pleasant job stripping a carb, but last year I did get away with a good spray of cleaner an air filter clean and then left the mower chugging away with a cable tie round the "dead mans" for a half hour.

AB From the well pummelled keyboard of Archibald Tarquin Blenkinsopp Esq

A bit extreme?

The gunge left after the more volatile elements is a pain to remove, but not really too bad in my Homebase Soveriegn.

I think most mowers are of a similar design incidentally.

About two hours max for the full stripdown cleanup and reassembly. Fresh petrol would maybe clean the carDoesb.

The cost of cleaner is so cheap though, I bought two spray cans which will see the mower out, no doubt

Does anyone do two stroke mowers?

I scrapped two Chinese strimmers last year due to fouling in the carb and also in the excuse for a fuel filter.

I must admit, the "carb" was unrecogniseable as to it's functioning. Even after finding some stuff on the net, the work involved was not practical.

I bought a Ryobi electric strimmer from Amazon. Not as much wumph, but easier to use and less troublesome.

AB From the well pummelled keyboard of Archibald Tarquin Blenkinsopp Esq

A Yamaha generator loosely wrapped in a plastic sheet sat behind my garage for three years. It still had some fuel sloshing about in it. Decided it was worth a shot and it started on the third pull.

Lawnmowers and generators generally seem to have maintenance-free engines, well mine do at any rate, whether intentionally or not.

Along with aircraft engines, the secret is low RPM and somewhat simple design

And restricted running hours

Having been brought up on this idea (starting with motorbikes more than

The old issue with two strokes, of oil left in the float bowl after the petrol has evaporated and then blocking jets and jamming throttle slides also seems to be less of an issue (helped by ratios of 50:1 rather than

A few years ago I inherited a rotovator (genuine Honda) that had not been run for three years. It still had fuel in it. I removed the plug and turned the engine over three or four times to check that the bore hadn't rusted. Put the plug back in and it fired first pull.