Ethanol/Petrol and the colour of plugs?

[LJ.]

Looking at another thread... "Spit back through carb and backfires" http://www.audioworld.net/BSA/forum/index.php/topic,3693.msg25436/topicseen.html#msg25436 I can't help wondering if Ethanol is affecting the colour on plugs that we have been used to seeing.
Jim Lawnmowerman mentions...

never the chocolate brown colour they should be

Has anyone any thoughts about this?

[lawnmowerman]

Hi LJ

I have a mate who has access to aviation fuel and have a 20L canful so I am going to run on that when I get the MOT done. There is no ethanol in avgas as they are not allowed to mess around with it for safety reasons. It costs a fortune but will be interesting to see if it makes any difference - should go a bit better as it is 103 octane  

Jim

[bsa- bill]

Could be we are blaming Ethanol when the cause might be elsewhere, I'm thinking that the issue of black plugs might pre-date the use of Ethanol in our petrol.
Rather easy to just blame the latest change so we need to determine some facts first
When was Ethanol first put in petrol?
Could it have to do with the withdrawal of Lead
What else has changed in petrol since the days when our bikes were in daily use.
The views of anyone who uses an A10 on regular longish runs should be sought

Otherwise might as well put it down to the withdrawal of Green Shield stamps or the missing Tiger Tail sticking out of your tank

[lawnmowerman]

Very true Bill.
Hopefully when I try the avgas it may reveal the way ahead as it has lead and no ethanol. It may be that I need to use it for a while to reveal any changes and I may need a second mortgage - it is about £1.90 a litre! It should be an interesting experiment though.
It may also have something to do with the current manufacturing standards of spark plugs - I think I have got some 60s plugs in a box somewhere............
Jim

[sinbad]

 Hi Jim, regards your last comment abt 60s plugs I believe the letter R on current plugs stands for resistive I looked into a broken one and unless I missed something what I found was a large air gap. I don't think this is suited to our machines.
Rod.

[lawnmowerman]

Yes you are right Rod

I telephoned the help desk at NGK last year and they recommended a resistive plug and when I said they were not suited to mag ignition he said that they should work unless the mag is on the way out. In the end I went for non resistive plugs.

Jim

[bsa- bill]

Just a thought guys but is there a difference between resistive plugs and resistor plug caps

Although thinking about it there was a practice ( maybe not a common one) back in the day of cutting HT leads and inserting pins in from each direction then joining the ends up to leave an air gap - alleged to give a better spark, never tried it myself

[muskrat]

G'day all,
            I'm sure it's the unleaded fuel not the ethanol that's giving us black plugs. A hotter plug helps, say a B6ES in place of a B7ES. I never run ethanol blended fuel in any of my bikes.
Cheers

[sinbad]

Hi Bill, there was a gadget came out called a booster or something had a pre-set gap in it,fitted in the plug lead they didn't catch on or last very long.R plugs are resistive as are some plug caps I use the non resistive rubber caps.
Rod.

[alanp]

Rod, as I understand it the 'booster' is/was the kiss of death to mags. I say 'is' because it's still out there on sale. I bought one new at an auto jumble last year and didn't fit it when I realised what it was.

[MG]

Alan, is that the "booster" you were talking about?

http://cgi.ebay.co.uk/MAGNETO-MOTOR-CYCLES-SPITFIRE-MULTISPARK-IGNITION-/270668024757?pt=UK_Motorcycle_Parts&hash=item3f05124bb5

I almost bought one at an autojumble, just out of curiosity, to cut it open and see what wonderful world of sparking miracles was hidden in there   . But then decided to rather spend the 10 quid for some cold refreshments.  

[groily]

The only mag I ever saw that had been running with these booster things in the plug leads had HT pick-ups that looked like pumice stone - literally - from arcing on the inside, and the HT winding (not long rewound) gave up soon after. That was a K2F on an 88 Dommie. Shouldn't need them, and like MG, best spend the money in the nearest beer tent.
As for ethanol, apart from having bad consequences for fuel lines made of old materials, I haven't noticed anything different in plug terms. French jungle juice is allegedly well 'ethanolised' but the plugs look just the same on my bikes (a bit black) as they have since unleaded came in. There's no benefit, generally speaking, in running on octane ratings higher than the engine needs NOT to pink or otherwise misbehave; but maybe there are a few more calories in 103 Avgas, a bit like in a chocolate éclair or a very good ale.
Broadly speaking, I'd say that any mildly-tuned engine that needs add-ons in any department to make it go has something on the cusp of failure or set up wrong. Resistor plug caps, like 'butterfly' Champions, seem to me to create no difficulties with mags, and the modern NGK jobs ditto.

[sinbad]

Alanp,I am amazed I thought that thing was killed off in the sixties, cheers Rod.   

[iansoady]

But as they say, there's one born every minute....

[cus]

My bike runs a 389 carb, b6es plugs & 98% oct. fuel. Runs beautifully on the
open road but hates town, ie. stop start traffic. Reading older posts, I changed
my slide from a 3 1/4 to a 4, & all is good now, plugs are good colour after idle
& town riding, new slide from Hitchcocks was chromed too, which I'm sure will
help with wear. A mate of mine also suggested going to a smaller needle jet to
cure richness, but at this stage all is fine,

regards, Cus

[brackenfel]

I never use anything with a resistor in for my older bikes, plug or cap.. If I recall resistors were put in to minimise radio interference back in the old days.. If you're running 12v & a coil / electronic ignition then fine, but as far as I'm concern the spark from a mag doesn't need any more resistance than absolutely necessary between it and the electrodes..!!
Some modern plugs are simply cr*p, had several NGK ones die suddenly for no good reason.
Much as I'd like to I don't think we can necessarily blame unleaded for this. Probably just as well as we're stuck with it, around here at least..

Cheers,
Adrian