This question has probably been asked before but there doesnt seem to be a search function on this forum and i did look back 4 or 5 pages to see if there was a recent topic on this.

What spark plugs would the forum recommend for my NC35?

At the moment, everything in my bike is stock. The bike is mainly used for road riding/commuting but even so, i do ride from 9k RPM to 14k RPM very often because its incredible fun

Where i live, in Southeast Asia, people seem to favour the ER8EH or ER9EH. What does the forum think about these?

Im also leaning towards iridium plugs of any brand. Ive read that they tend to last longer than "standard" plugs. Please correct me if im wrong about that.

I'm currently using ER9EH and they have been great..i'm not too sure on the iridium plug bit though.

I wouldn't bother with iridium plugs. They last longer but they cost more. I'd rather change the plugs more often and use the cheaper variety.

I concur with the above, stock er9eh-9 are fine.

you can get iridium in the same size, er9ehix or somethign like that.

unless they are cheap i wouldt bother unless you are doing mega mega miles on 400 and plug life is a worry, stock plugs last a long time.

Thank you jedidude04, lukemillar and neosophist for your recommendations!

I asked on a local forum (in my country) and the feedback was also the same. The stock configuration of ER9EH plugs seem to be the most cost effective choice!

However i did notice some NC35s using different heat ranges like 8 or even 10 to suit their own setting.

The mechanic that helps me with tuning swears by Denso IY27s though. I will update again once i make my decision.

The higher the number the "colder" the plug is. Cold plugs dissipate heat better if you spend more time at high RPMs (spirited riding/track/race). "Hotter" plugs, however, tend to start easier in the morning when the engine is cold. I'm sure ER9EH and ER10EH will be fine for most if not all cases.

Sad to say they are the most "cost effective" solution when they are about $15-20 per pop though.