Sparkplug failure

[Daniël Bos]

Yep...

[GardenKit]

I know I should not really ask this, as I am sure you know how to fit plugs and I do not wish to offend, but assuming the first failure was just one of those things, could the next two be due to fitting with a poorly fitting spanner, which if twisted just a little, could crack the insulator. It does happen.

[Daniël Bos]

Tis not such an odd question, I use a box spanner with the spanner bit squeezed in rather than squeezed out if that makes sense. So the pipe bit is bigger than the spanner, so not much chance of damage I reckon.

[shanks]

Would over-tightening the plug in its seat cause such a problem?? I imagine it could.

[spudulike]

Would over-tightening the plug in its seat cause such a problem?? I imagine it could.

 

No - it would just weaken the thread and risk having the plug blow out of the hole.

 

My money is still on the plug cap having some sort of carbonised track between the metal HT connector and the base of the plug cap and would personally change it for the pennies it costs!

 

I have never had a faulty plug and have only ever had a problem with arcing on one plug cap that a new one cured.

 

Very strange this one, NGK plugs are usually very reliable and rarely fail or wear badly IMO.

[Daniël Bos]

I'm quite sure it's plugs not the cap.

When I'Ve replaced the plug before, I tried the plug coming out in another saw which then displayed similar problems and a very weak spark.

New plug, both saws running fine and sparking well.

[pleasant]

Doesn't really leave a lot else but the ignition module although it would be a first if it were causing plugs to fail. But given everything else it would be worth obtaining a used known working one to test the theory.

[spudulike]

Doesn't really leave a lot else but the ignition module although it would be a first if it were causing plugs to fail. But given everything else it would be worth obtaining a used known working one to test the theory.

 

OK - perhaps the ignition coil is going bad or maybe the coil to flywheel gap is a little large, with a new plug, the spark works but as it gets old, it doesn't spark so well.

 

It doesn't explain the weak spark when tried on other machines though:confused1:

[Daniël Bos]

Would it be possible it has something to do with the kind of usage it gets?

It's mainly used by my brash-bitch, and often only makes one or two cuts, then gets switched off, then another cut etc etc. so it does not often get proper hot, but does work about 4 hours a day I guestimate, just in short sprints.

 

There may be something with the coil though, he often finds it a little harder to start when it's warm, but I've not had any issues with that and reckon he's just a bit limp-wristed.

[GardenKit]

Any chance of a good picture or two of a failed plug?