Hi all. I'm new to petrol lawn mowers but have inherited a Power Force DYM1481FB lawn mower which starts, should I use the primer, and then cuts out after a few seconds. Suspecting this to be a faulty carb I ordered and fitted a replacement but still no joy. In fact nothing at all now.

Before I start investigating further I noticed the small 'spacer' that sits between the carb and the body has a small groove on one side. If I can get a photo of this later I will post. I cannot seem to find out what this is for or in which direction this would fit? Do any of you have any idea please?

Hi Chris, and welcome to TGMF.

The groove on the insulator (spacer) is to let the back of the carb breath.  You should see it line up with all the holes in the large gasket (heat shield) and the smaller inlet gasket which sits between the carb and that large gasket. There will be a hole in the rear of the carb where it mounts which should line up with those.

Insulator and Gaskets should sit like this.

Insulator



This large one against insulator (spacer)



then this smaller gasket



Then carb. 

Quote from: Mick on August 04, 2024, 09:09:12 AMHi Chris, and welcome to TGMF.

The groove on the insulator (spacer) is to let the back of the carb breath.  You should see it line up with all the holes in the large gasket (heat shield) and the smaller inlet gasket which sits between the carb and that large gasket. There will be a hole in the rear of the carb where it mounts which should line up with those.

Insulator and Gaskets should sit like this.

Insulator



This large one against insulator (spacer)



then this smaller gasket



Then carb. 

Thank you so much Mick.    I thought that but just wasn't sure. Brilliant. I'll refit everything and see what happens. Not holding my breath though. 

Assuming you have the correct carb, you could try giving it a shot of fuel directly into the intake just to see if it starts again, that will confirm you have a fuel issue. If it till doesn't do anything try a new plug, and or make sure the OPC cable stop cable is actually not preventing i from starting, Pull the lever up and give the cable an extra tug by hand and then try starting it.

Hope it works out ok.

Quote from: Mick on August 04, 2024, 12:05:55 PMAssuming you have the correct carb, you could try giving it a shot of fuel directly into the intake just to see if it starts again, that will confirm you have a fuel issue. If it till doesn't do anything try a new plug, and or make sure the OPC cable stop cable is actually not preventing i from starting, Pull the lever up and give the cable an extra tug by hand and then try starting it.

Hope it works out ok.

Unfortunately, I couldn't find a carb specific to the model so purchased one off AliExpress. All is exactly the same, except for the butterfly valve, which works in the opposite direction. I've removed the one from my old carb and replaced it with the new carb. I've just tested the magneto  coil with the multimeter and its returning a zero reading across the spark plug lead to the body/connection points. I've ordered a replacement and will go from there. Thanks for the invaluable advice.

Quote from: chris301up on August 04, 2024, 01:09:43 PMUnfortunately, I couldn't find a carb specific to the model so purchased one off AliExpress. All is exactly the same, except for the butterfly valve, which works in the opposite direction. I've removed the one from my old carb and replaced it with the new carb. I've just tested the magneto  coil with the multimeter and its returning a zero reading across the spark plug lead to the body/connection points. I've ordered a replacement and will go from there. Thanks for the invaluable advice.

I don't bother with the multimeter, I just check to see if it has a spark directly from the end of the lead to the head. It will either have a spark or not.

So your old carb might actually be ok unless you found it badly corroded or gummed up.  I found one here though I don't know the company. https://solenttools.co.uk/product/solent-tools-carburettor-compatible-with-tesco-dym1481fb/

Also a coil https://solenttools.co.uk/product/solent-tools-ignition-coil-compatible-with-tesco-dym1481fb/

The carb looks exactly like the one used on the small Cobra mowers.

Quote from: Mick on August 04, 2024, 01:26:34 PM

Quote from: chris301up on August 04, 2024, 01:09:43 PMUnfortunately, I couldn't find a carb specific to the model so purchased one off AliExpress. All is exactly the same, except for the butterfly valve, which works in the opposite direction. I've removed the one from my old carb and replaced it with the new carb. I've just tested the magneto  coil with the multimeter and its returning a zero reading across the spark plug lead to the body/connection points. I've ordered a replacement and will go from there. Thanks for the invaluable advice.

I don't bother with the multimeter, I just check to see if it has a spark directly from the end of the lead to the head. It will either have a spark or not.

So your old carb might actually be ok unless you found it badly corroded or gummed up.  I found one here though I don't know the company. https://solenttools.co.uk/product/solent-tools-carburettor-compatible-with-tesco-dym1481fb/

Also a coil https://solenttools.co.uk/product/solent-tools-ignition-coil-compatible-with-tesco-dym1481fb/

The carb looks exactly like the one used on the small Cobra mowers.

Yes. It could be that the carb was okay? I automatically decided to buy as the mower started briefly after priming and then cut out after around 5 seconds or so. I couldn't see a spark at the spark plug so have stripped it down again and tested the magneto coil. It looks like that is the potential issue? Thanks for sourcing the parts from Solent Tools. If the new carb works then I'll leave well alone. I can always put the butterfly valve back into the old unit should I need to? Many thanks again

No problem, hope it goes ok. Let us know how you get on with it. 

Quote from: Mick on August 04, 2024, 01:38:51 PMNo problem, hope it goes ok. Let us know how you get on with it. 

Evening all. I've finally got round to having a go at repairing this lawn mower. I still cannot get it to run, Although it will start briefly. Just to say I've replaced the carb, spark plug and magneto ignition coil. I have managed to get it to start if I hold the governor (I think thats what its called) control link but then it stops. I just cannot understand how this works. Have been looking online for an engine diagram but not having much joy. So thought I'd ask you knowledgeable people if you can advise?. I just cannot understand how this works?