NGK plugs for 500

[McCabe-Thiele (Ted)]

I have no idea when or where I bought them - I have a set of new NGK DR7EA plugs.
DS show the 500 plug as NGK DR7ES.

Can I use these DR7EA no idea what the S means compared to A ?

[deltarider]

So far nobody knows. Why did you choose 'R' plugs?

[Johnwebley]

I don't think ES are available,
The DR are resistor plugs
Could cause issues if used with resistor plug caps

That leaves D7EA,
Or if you ride harder D8EA

same as 400 and 750,

I use Denso equivalent, and an very happy

Sent from my SM-A546E using Tapatalk

[Bryanj]

Ted, if you can find any D7EV are the dogs doodads for the 500, it should have had newish D7EA in it when you got it, D7ES is the original and not available the A is same as S according to NGK. You should not be using the R type

[McCabe-Thiele (Ted)]

So far nobody knows. Why did you choose 'R' plugs?

I have no idea, I can't remember when I bought them either.

I do have a set of Denso X22ES-U plugs.

I think my bike had  NGK D7EA fitted .

[McCabe-Thiele (Ted)]

Ted, if you can find any D7EV are the dogs doodads for the 500, it should have had newish D7EA in it when you got it, D7ES is the original and not available the A is same as S according to NGK. You should not be using the R type

So a resistor spark  plug when you have resistor plug caps does this cause a problem somehow ?

[deltarider]

Not necessarily, but realise you'll then have a total of 20kΩ resistance in a circuit... Personally I consider that a lot and it is not needed. The French manual, that has been composed in colloberation with Honda France, advises to replace plugcaps when they read 8kΩ or more. Claims made by some members of the international forum - and nowhere else! -that adding resistance is benificial for spark duration, have so far remained unproven. And even then it remains to be seen it will effect in better running.

[Seabeowner]

I ran resistor plugs and caps for years and didn't have a problem. I think DSS sells the R plugs for the 500. But I must admit I now use non R plugs.
My 71 500 came with 7.5k plug caps from new I believe.

[K2-K6]

I ran resistor plugs and caps for years and didn't have a problem. I think DSS sells the R plugs for the 500. But I must admit I now use non R plugs.
My 71 500 came with 7.5k plug caps from new I believe.

I've not experienced the purported problems that's often attributed to doing this either.

Often given out as a "No no" but without substantiated evidence to prove there's inherent problem by doing so.

I'd run them Ted, then you'll get at least personal experience of this with your own setup.

[McCabe-Thiele (Ted)]

My experience on cars before individual coil packs arrived was that many used resistor caps and resistor plugs without problems with one coil on 4 & 6 cylinder engines so it's a new thing for me to consider it.

[Bryanj]

I have always used NGK resistive caps and non resitor plugs simply cos thats what the rep said, never asked why as he was very knowledgeable

[deltarider]

Two dealers in Holland that work on these bikes on a daily base have reported problems with resistor plugs on our bikes. Trigger has reported the same in: http://www.sohc.co.uk/index.php/topic,28181.msg264374.html#msg264374
It's a year old debate. I don't see any advantage whatsoever adding resistance over what NGK recommends.

[K2-K6]

Worthwhile trying them Ted, then you can form your own view and report the effects, if any, to forum for our appreciation 

[Toko_Jo]

It's a year old debate. I don't see any advantage whatsoever adding resistance over what NGK recommends.

For a change I actually agree with you DR