Getting an old engine going again.

[Tim Stobart Tree Surgery]

Hi all, I got given an old JCB mower yesterday by a customer who I know cut the grass for. He's not used it for a couple of years (as I've been doing it with mine). Needless to say, it didn't start, even with fresh fuel.

 

What I'd like to know is how would everyone go about getting it going again?

 

My fairly simple approach will be to drain and change the oil, change the spark plug, and maybe the air filter. If that wee lot doesn't get it going, what's the next steps to try?

 

Cheers.

[agg221]

To run it needs fuel, a spark and compression, all at the same time in the cylinder.

 

Since you have put fresh fuel in I would take the plug out, see if it's wet, wipe it clean, check the gap and check it sparks against the side of the head while pulling it over.

 

Assuming there is a good spark, I would then put the plug back in and pull it over a few times (full choke), then take it back out and see if it is wet.

 

It could just be that there is some old fuel or water somewhere in the line which needs clearing through before it will run.

 

Alec

[Tim Stobart Tree Surgery]

Cheers, I'll try that.

[spudulike]

Alec is pretty much spot on and have been using that logic for around 40 years now.

 

If the saw was running before then it should work again. Most non startes are fuel related issues tbh, that or two stroke seizes on the saws I work on.

 

If the machine is reluctant to fire but has spark, compression and fuel, heating the park plug up on a gas hob (if the other half isn't around) or with a plumbers torch helps reluctant engines, especially low compression or flooded ones - it helps vapourise the fuel:thumbup:

 

An old timers trick but it has worked hundreds of times!

[ArthurBottlesworth]

Did you empty old fuel out before topping up?

 

I'd use bit of easy start ( or wd40) down inlet first time too, once it fires it should just go

[Tim Stobart Tree Surgery]

Did you empty old fuel out before topping up?

 

I'd use bit of easy start ( or wd40) down inlet first time too, once it fires it should just go

 

It was bone dry, so no, there was no fuel to come out, although I did get a wee spider out of the tank.

[CallumA]

you can also after checking that there is spark put a small amount of petrol in the cylinder and give it a pull. works every year on the old rotavator which gets parked where it finishes until next year!!

[s.varty]

you can also after checking that there is spark put a small amount of petrol in the cylinder and give it a pull. works every year on the old rotavator which gets parked where it finishes until next year!!

 

[Peasgood]

After a lifetime of having engines not start i would say Easy-start is way too harsh.

For long enough I used a gas blowlamp into the air filter instead. I now prefer aerosol brake cleaner.

Does the same thing but without all that knocking and banging.

[jay2578]

Check for a sediment bowl on the carburetor, if there is one give it a good clean as usually full of crud.

Perhaps also give the carb a good blow out.