Plugs are plugs. The HD ones have always worked fine for me.

 

NGK Plugs

DCPR7E stock
DCPR8E one step colder
DCPR9E two steps colder

As I had said in my previous post, I run one step colder.
I always buy 4, and run the 2 that index the best.

I quit running Champions when the threads kept getting buggered up.
No problems with the NGK's.

I've heard bad stuff about the irridiums.

 

This goes back but why would you run a hotter or colder plug than stock?

 

same question as miked...
and, what have u heard about iridiums that has tipped u off Ed?

 

Issues on the dyno near WOT, and another guy that couldn't get past 105 MPH after installing them. Replacing them with stock cured both guys problems. Those were the only two I heard of. Suspect it's more of an ecm thing, than the plug itself. Different kinds of metals do different things at high temperatures. I doubt any carbed bikes would notice anything.

Considering how long a stock plug lasts, and how inexpensive they are, no need for me to invest in irridium.

As far as the colder plug thing, read up about "reading plugs" and you'll be able to tell if your current plugs are running too hot or not. If you are running higher compression, a colder plug can help avoid ping. They dissapate heat faster from the electrode.

 

IMHO I wouldn't put a hotter plug in. No reason to unless something is wrong with the tune. I run one step colder on a fairly stock bike. Not sure if it buys me a thing, just a habit from my last hot rod bike. As Ed stated, the colder plugs dissipate heat better.

 

hmm ok, I get it, thnx...
so in colder weather it is adviseable to use hot plugs and the contrary on hot weather, that's make sense... well... as I'm in the tropics, colder plugs don't sound necessary...thnx for clearing it