Petrol lawn mower new lease of life

those two very important.

not such an issue. is it a magneto system? #

it is said that fuel only lasts a few months before it isn't any use. If the fuel has been in the tank/carburettor for more than a year, I'd replace it with fresh stuff.

You may find that the main jet in the carb is gummed-up. Carb cleaner may work, but new carbs from feebay are cheap.

Fresh fuel and remove air-filter to pour a bit of petrol into the carb.

Thanks very much all. Not sure what you meant by a magneto system but it is a Briggs and Stratton engine with a pull chord start mechanism.

Hope that helps

Lee.

Probably not a bad idea, though I've never experienced problems with fuel left in the mower/strimmer over the winter. I do top up both before use but that will be fuel from the can that might be the previous seasons or even the season before. The can is vapour tight and kept in the garage which is always cool. Tanks have breathers to let air in as the fuel is used, may also let volatiles out if the fuel gets warm.

Check for spark?

Check the oil level and drive components for lubrication (chain and bearings if a cylinder mower). Check things move and aren't seized.

A rotary I'd be tempted to just try it but if it showed no sign of life after a couple of pulls replace the fuel, check spark etc. A cylinder I'd check the drive for lubrication and freeness first.

So what happens to all the power then? Brian

Was just thinking... What do I do with the old fuel?

Have a car? Bung it in that, even if it's as diesel. Less than a pint of petrol in a couple of gallons of diesel isn't going to be a problem. If worried fill the car up then add it.

Or wave good by to your eyebrows using it to light a BBQ. B-)

Its a magneto system, it doesn't need a battery to be connected, provide the ignition voltage, the voltage is generated by a magnet spinning past a coil.

I've had starts up to 2 years, but a 3 year old tankful would not start

- ride on westfield lawnmower with electric starter - but adding a tank of fresh got it going

use it as an additive

oh - no battery then

a magneto.

if you don't know what that is not much point me telling you how to set the points!

Or even possibly that the gasket inside the carb has disintregated. Spare ones are easily obtainable.

Ah! Okay, those are simple. Think FAST -- fuel air spark timing.

(Timing is generally only a problem if it has hit something very hard -- there's a shear key inside that shears to protect the crankshaft, and then the timing is off... replaceable in minutes, once you have done it a few times.)

I'd do this:

Drain all fuel, replace with fresh fuel, check oil, prime, pull, pull, pull, ....

No luck?

Shot of ether/StartYaBastard into the air cleaner, pull, ...

No luck?

remove plug and see what it looks like, see if it sparks outside the cylinder. etc.

(... and then continue by reading the text where I learned the above:

Thomas Prufer

Nip down to Halfords and buy a can of "Easy Start".

i'm about to try a similar product (bought off ebay) on my hedge trimmer.

It's worth checking that the HT lead is still intact and is making good contact with the sparking plug. I tend to unplug the HT lead when I'm working under the mower (eg cleaning out the munched-up grass that sticks to the walls of the mower) as a safety precaution. A mower will not start (!) if you forget to reconnect the HT lead and it is only resting on the top of the plug ;-) A damaged lead will have the same effect. If the mower (with a magneto) is very difficult to turn, even though there is nothing stopping the blade turning, you might have a short to ground in the HT system. Or you might just have a damn good compression ratio!

Do modern mowers with electronic ignition actually use a magneto - a generator that directly produces HT - or do they use a low-voltage alternator and a coil, as for a car engine? Presumably electronic ignition doesn't need a contact-breaker but instead can use a Hall effect magnetic sensor to control the spark timing and advance/retard.

Changing the air filter may also help.