Unusual spark plug failure

[Norfolk]

Last year I fitted turn indicators running direct from a battery which have given no problems whatsoever, however......last week i went to use the scoot it would not start, did the usual trick of exchanging the spark plug with another that has been used on occasions, however..........using the indicators with the engine now running they were flickering very fast, engine performance etc was unchanged. Turned engine off...and indicators worked ok ! !
Tried all sorts of things but could not understand why they should suddenly be problematic ........what is now different.
Put old plug back in, started engine and indicators now work ok !

Norfolk

[steveg]

I don't know the answer, but I wonder if it might be worth giving a resistor spark plug a try

WHEN SHOULD I USE A RESISTOR SPARK PLUG?
A: NGK "R" or resistor spark plugs use a 5k ohm ceramic resistor in the spark plug to suppress ignition noise generated during sparking.

NGK strongly recommends using resistor spark plugs in any vehicle that uses on-board computer systems to monitor or control engine performance. This is because resistor spark plugs reduce electromagnetic interference with on-board electronics.

They are also recommended on any vehicle that has other on-board electronic systems such as engine-management computers, two-way radios, GPS systems, depth finders or whenever recommended by the manufacturer.

In fact, using a non-resistor plug in certain applications can actually cause the engine to suffer undesirable side effects such as an erratic idle, high-rpm misfire, engine run-on, power drop off at certain rpm levels and abnormal combustion.

[HxPaul]

Battery might have died,starting it may have charged it enough for the indicators to work but it couldn't hold a charge.

[MK Monty]

What kind of flasher unit do you have. The bi metallic ones rely on the resistance of the bulbs to turn on and off. Normally if you loose a lamp they flash quicker. The electronic ones stay constant. No idea why it's ok after swapping the plug. If they are LEDs then it could be interfearance

[Norfolk]

Hi Guys,

Many thanks for your replys, I have sorted out my own problem with the indicator interference by simply replacing the spark plug, the reason for posting the issue was to make everyone aware that with our scoots if anything can happen it will and can lead you on wild goose chase. Never assume anything ! !

The main issues being ; indicators have been working fine, scoot would not start, changed spark plug with another that has previously been used on numerous occasions with no problems, only on this occasion the plug decides to piss Me about and upset the indicators.

Norfolk.