Question about plug size/rating

[memper]

In my Haynes it says to use 6's. NGK parts finder says to use 8's.
I have a couple of NGK iridium DPR8EIX-9's. Can I use em?

Carbs have a stage 2 kit, FBF pipes and it runs a tad rich.

[Howie]

Get these, they will work just fine.  And they are now Ducati approved.

NGK DCPR8E NG4339

4439 gives you the correct head size and the removable terminal cap.  Should be less than $4 a plug.

[memper]

So Howie, are the ones you listed "8's"?
Will the spare iridium "9's" I have be too high of a spark? Not safe? I suppose if my current plugs are real sooty they might actually work out (considering they are of equal length).

[ducpainter]

The plugs howie listed are 8's.

9's would be hotter.

If you need 9's you have a fueling problem

[memper]

gotcha

[koko64]

In my Haynes it says to use 6's. NGK parts finder says to use 8's.
I have a couple of NGK iridium DPR8EIX-9's. Can I use em?

Carbs have a stage 2 kit, FBF pipes and it runs a tad rich.

I use those iridiums. 8 for NGK heat range and -9 for quite a large gap. Those large gaps may be a bit too much for stock coils, but can work well with high output coils and leads.
One day, when there are no wars and poverty is eradicated, the spark plug manufacturers will use the same number codes.

[motoxmann]

um, aren't higher numbers Colder plugs? meant for use in hotter engines and/or hotter weather? meaning a 9 would be too cold in a stockish Duc...

[koko64]

True for NGK, but is it Bosch or Champiom that go the other way?
The code isn't standardized unfortunately.
I remember a customer getting what he thought were Denso equivalents to Champion and NGK plugs for his hi comp M944 and having problems..

[ducpainter]

True for NGK, but is it Bosch or Champiom that go the other way?
The code isn't standardized unfortunately.
I remember a customer getting what he thought were Denso equivalents to Champion and NGK plugs for his hi comp M944 and having problems..

Champions use lower number for colder plugs.

[koko64]

Champions use lower number for colder plugs.

Thats right, a never ending cause of confusion.
I remember way back in my Harley ridin' days...  My "bros"  warned against those "crap NGKs always foulin', stay with Champion". 

[ducpainter]

Thats right, a never ending cause of confusion.
I remember way back in my Harley ridin' days...  My "bros"  warned against those "crap NGKs always foulin', stay with Champion". 

I used to used the fine wire electrode 'G' plugs in my 2 stroke.

Back then we'd use auto coils, for the increased voltage, and wide gaps with the fine wire plugs and never oil foul a plug.

[koko64]

I used to used the fine wire electrode 'G' plugs in my 2 stroke.

Back then we'd use auto coils, for the increased voltage, and wide gaps with the fine wire plugs and never oil foul a plug.

I was alluding to market prejudice.
NGK are the plugs of choice for me. I run big gap iridiums with strong coils.
Back in the day, some people had issue with where the plugs were made (and confusing the plug codes). Didn't bother me, I ran a Mikuni flatslide on my Harley when everyone else ran S&S, if you know what I mean.

[ducpainter]

I was alluding to market prejudice.
NGK are the plugs of choice for me. I run big gap iridiums with strong coils.
Back in the day, some people had issue with where the plugs were made (and confusing the plug codes). Didn't bother me, I ran a Mikuni flatslide on my Harley when everyone else ran S&S, if you know what I mean.

I got it...