Author Topic: SPARK PLUG DIAGNOSTICS  (Read 135 times)

Offline Nurse Julie

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SPARK PLUG DIAGNOSTICS
« on: December 04, 2018, 09:07:35 AM »
Found this on another site which I thought was interesting. This example is for the resisted plugs and as we know, you shouldn't use resisted plugs with resisted caps but it gives a good indication of what we can look at to help diagnose a problem.

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Offline Bryanj

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Re: SPARK PLUG DIAGNOSTICS
« Reply #1 on: December 04, 2018, 11:54:33 AM »
Years ago our NGK rep, an ex racer called Stan Dibbden, explaned to me you get the mixure from the flat face and plug range from the porcelain which ties in with the picture. Might be worth asking Steve to move this to a different section.

Offline Rob62

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Re: SPARK PLUG DIAGNOSTICS
« Reply #2 on: December 04, 2018, 01:06:14 PM »
I have read that modern petrol with its high ethanol content and other additives, makes traditional plug-reading less reliable.... has anybody else any views on this?.

I have used plug reading myself as a guide, especially on my 2-strokes and I think it is ok. But If I suspected a serious condition I would be tempted to have a more reliable diagnosis i.e. gas analysis on a dyno.

Offline Nurse Julie

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Re: SPARK PLUG DIAGNOSTICS
« Reply #3 on: December 04, 2018, 01:38:22 PM »
By what I have observed on my plugs, I think the above illustration is still a very good guide to sorting out minor problems yourself. Never had a bike near a gas analyser or a dyno either. I'm still not getting what the issues are with ethanol, we use supermarket fuels 100% abd have encountered no problems whatsoever. Maybe its because all our bikes are ridden regularly and we fit Viton O rings to everything.
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Offline moorey

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Re: SPARK PLUG DIAGNOSTICS
« Reply #4 on: December 04, 2018, 08:05:29 PM »
The only problem I have had was one length of fuel pipe going rock hard and cracking which to be honest could have been down to it been cheap shite fuel line rather than the ethanol in the fuel.

Offline Rob62

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Re: SPARK PLUG DIAGNOSTICS
« Reply #5 on: December 04, 2018, 09:25:49 PM »
I’ve never had any problems either...but I avoid supermarket petrol, or any 95 RON, like the plague. The only exception would be Tesco millenium which is great value premium fuel and 98 RON, but i dont have a local source.... even the car requires 98 RON so i get used to buying it  :-\