Forum

[Presto]

Thanks Norm - just goes to show that theory doesn't always match up to experience. Clearly there is a problem that you and others have with these plugs. It would be good to know exactly what causes this problem. I agree that if they fail in certain casaes as frequently as that they are too expensive to keep replacing.

[Barry_Q]

I've tried iridium plugs in both of my bikes. Neither machine liked them. Slam in a bog standard NGK and they work every time.

[Beezabryan]

Can't remember when the Iridium plug went into our Bullet, at least four years but more like six. last seen 4 years ago until yesterday when prompted by this thread I took it out & it looks the same as last time. Seems to work for some but not others

[MadMike]

Irium plugs are usually designed and manufactured to suit a particular engine specification for each manufacturer. They are acknowledged as being a better product for higher revving multi cylinder engines, usually with injected motors. They are also acknowledged as being detrimental to consumption particularl and often performance in "simple" slow revving engines. In an Enfield, or my Red Hunter or my Model 50? A resounding no. They are a pointless and expensive item in those sorts of engines.

[Beezabryan]

You may well right Mike and probably are but I ain't going to spend good money to mend summat that ain't broke

[Frank]

Had one in my Electra X for the last 4000 miles without problem. I did have to turn the idle speed down quiet a bit when I fitted it, so it must have made a difference for the better. Everything else as standard, runs on non ethanol super unleaded, never misses a beat and gets 110 mpg. How much is down to the plug I don't know but I'm not going to change a winning formula.

[Bertie the Bullet]

So after Bertie broke down due to a duff condenser ( lucky I always carry a spare ) I ordered a new one and a new plug at the same time, I decided to go for the Iridium plug at much extra cost after seeing lots of hype in previous posts, have I wasted my money?

[Leon Novello]

No, Bertie; just fit and forget.

[Norm]

Only you can work that out Bertie

[MadMike]

Bertie IMHO and in a word.........yes. nobody has yet put their Enfield on a dyno, tested it and then replaced the plug with an Iridium one and retested to measure the results. In most cases the "improvement" is in the mind of the rider and is a result of believing the hype and thus deducing that power etc must have improved. If like Bryan you have fitted one, and it has done more miles than a standard plug then that is fine with me. To counter this though My Model 50 still runs on a 20 year old Champion plug, and the one in my Ariel was fitted in about 1980. The significance of this is nothing really except to show that some plugs seem to last forever regardless of their type. HTH.