DEFECTIVE SPARK PLUGS

General purpose topics/chat goes in here
56G80S
Member
Posts: 3354
Joined: Wed Oct 12, 2005 10:45 pm
Location: N YORKS UK

Re: DEFECTIVE SPARK PLUGS

Post by 56G80S »

All off topic but initially the problem affected less than 10% of fuel stations. Slow news day, ramp it up and panic buying ensues. Supply a problem!

Everything blamed except the lack of preparation for an event (Brexit) which had a 2.5 year lead time. Also the failure of haulage companies to carry out changes to working conditions, pay and reward for carrying hazardous material. Why drive a petrol tanker when the supermarkets will pay more for driving a standard unit full of food?

Ironically, Sainsburys, Morrisons and Co-op petrol supplies were unaffected before the panic hit.

Johnny B
Reynard24
Member
Posts: 362
Joined: Mon Dec 16, 2013 2:27 pm
Location: CAMBRIDGESHIRE UK

Re: DEFECTIVE SPARK PLUGS

Post by Reynard24 »

My apologies for driving this off topic - I was caught in traffic chaos caused by half-wits panic buying fuel that is not in short supply, even if that was a reason to do it, and needed to vent frustration.
In answer to the original post I have never experienced a faulty plug but have just replaced my first faulty coil.
JEAN-NOEL
Member
Posts: 601
Joined: Wed Oct 12, 2005 10:45 pm
Location: FRANCE

Re: DEFECTIVE SPARK PLUGS

Post by JEAN-NOEL »

Hello gents,
the saga continues! Today I did another test.After starting with the right N3C & N4C, I removed the spark plugs to replace them with the 2 defective N3C & N4C: no spark even though they had produced one (weak) with the electronic ignition of the lawn mower! And by testing the two good spark plugs under the same conditions they produce the same spark on the right and on the left.
The mystery thickens ...
JEAN-NOEL
Member
Posts: 601
Joined: Wed Oct 12, 2005 10:45 pm
Location: FRANCE

Re: DEFECTIVE SPARK PLUGS

Post by JEAN-NOEL »

And the quality of the petrol has nothing to do with the problem, because I carried out the tests with the spark plugs removed and earthed on the cylinder heads.
Mick D
Posts: 2886
Joined: Mon Mar 24, 2014 5:44 pm
Location: Aberdeenshire

Re: DEFECTIVE SPARK PLUGS

Post by Mick D »

Hi

Is the 'failed' plug always on the same side? it sounds like you may have a dodgy lead or HT cap - works for a while when the plug is clean / new but is not conducting enough energy as the plug begins to foul.

Worth a look I think

Regards Mick
JEAN-NOEL
Member
Posts: 601
Joined: Wed Oct 12, 2005 10:45 pm
Location: FRANCE

Re: DEFECTIVE SPARK PLUGS

Post by JEAN-NOEL »

Last year, it was on the left cylinder, last week on the right one...Leads are new, the copper wires are splayed around the suitable split washers, all seems to be O.K. Indeed sparks are, visualy, the same on the right and on left plugs.
century
Posts: 90
Joined: Sat Jan 09, 2021 10:02 am
Location: Queensland AUSTRALIA

Re: DEFECTIVE SPARK PLUGS

Post by century »

ahhh world wide is the rubbish that is put out there by newsfolk,good thing we have bikes and the like to keep us on the level
bodgie dave
g5wqian
Member
Posts: 220
Joined: Wed Nov 18, 2015 7:43 am
Location: wiltshire
Location: near swindon wilts

Re: DEFECTIVE SPARK PLUGS

Post by g5wqian »

hi Jean noel ;
i remember my father telling me the slip ring in the k2f magneto can experience the brass surface wearing away due to brushes rubbing it away and then it may fire oddly .

one thing i have experienced myself is oil in the front of the magneto where the points are located , i think there is a small hole which allows oil "vapour" to come in via the timing case to give it some lubrication , all i did was to spray the points and cam ring clean using an aerosol of brake cleaner and blow it out with an airline .

i have had problems on my car using bosch equivalent sparkplugs and having them burn , and so found it was only any good using the correct ngk iridium plugs that work with coil pack ignitions .

i think electronic ignitions need resistor plugs and caps but i think you may have a magneto still with points so dont need any resistor parts on it .

hope you sort it soon
ian
Locked