Anybody reccomend the best spark plugs to be using in an nc30 race bike rather than the standard ones??

ER10 EH is the only other grade you can get.
You could at one time buy race plugs,But i remember them being £50 each.

Depends what you mean by 'rather than standard'? Do you mean different heat range, or different type? As far as I know, you'll only get plugs from NGK or Denso.

Standard is ER9EH (NGK) or Y27FER (Denso). Both also offer plugs that run hotter or colder (8/10 NGK, 24/31 Denso). All three appear on the NC30 fiche. The ER8EH/Y24FER is not listed on the NC35 fiche, although Tyga list it on their website for both. Often, you'll see them listed as Y27FER-C. I do not know the significance, if any, of the -C.

The only other different plug I am aware of is the Denso Iridium. It's the same heat spec, but has a much finer electrode at 0.4mm which allegedly produces a better spark, gives four billion mpg and five billion BHP etc.. These are sometimes sold as Y27FER, which isn't strictly correct, however they can also be found listed correctly as part IY27. Right now the best price on eBay is £11.30 each, which is a lot less than I paid the last time I needed a set!

Standard plugs are great - simple as that.

Cheapest standard ngk on the bay item number 260221591101

Next to Denso iridiums ones there is also iridium ones from NGK being same type numbers plus -IX- extension. I use these in my bikes as standard plugs. I have local address near me that may have expensive race plugs R847s. Who needs these?

Just had a reply back from my local supplier, limited supply of R847's in the -10- and -11- grades, ETA between 2 to 3 weeks after ordering and price tagged at a mere 60 euro each (!)

micpec wrote:limited supply of R847's in the -10- and -11- grades, ETA between 2 to 3 weeks after ordering and price tagged at a mere 60 euro each (!)

Until very recently they were available cheaply from the USA.

They now only have the 11 heat range in stock, only USD$20.

http://www.sparkplugs.com/product.aspx?zpid=10142

Edit: I wouldn't recommend using R847-11's on just a lightly modified engine, need higher compression race engines to make the most of these plugs.

Cammo wrote:

micpec wrote:limited supply of R847's in the -10- and -11- grades, ETA between 2 to 3 weeks after ordering and price tagged at a mere 60 euro each (!)

Until very recently they were available cheaply from the USA.

They now only have the 11 heat range in stock, only USD$20.

http://www.sparkplugs.com/product.aspx?zpid=10142

Edit: I wouldn't recommend using R847-11's on just a lightly modified engine, need higher compression race engines to make the most of these plugs.

Hi Cammo,
I'm trying to understand your older post above... In the '94 HRC RVF manual it does not show any modification engine internally (i.e. different pistons, rods, overbore, etc.), just the tranny gearing and the open HRC carbs set-up. And it does list the R847 10's and 11's for usage according that manual.

And reminds me of an older topic in 2009 (see below) that you mentioned that it is less prone to fouling with open hrc carbs set-up. And for that reason I believe this is why these plugs are listed in the hrc manual, and it does not make any difference when you do use it in standard engine.
Am I thinking correct?

viewtopic.php?f=24&t=8126&start=10

micpec wrote:Just had a reply back from my local supplier, limited supply of R847's in the -10- and -11- grades, ETA between 2 to 3 weeks after ordering and price tagged at a mere 60 euro each (!)

There was literally a box full of about 50 - 60 847s at the local autojumble the other month 4gbp each.. should have bought the lot...

i use denso ix iridiums, they last forever.

i wouldnt advice using the 847 race plugs unless you have a full hrc engine running a lot of wide-open throttle.. stock plugs / one heat range up will cope and run fine with almost every other varient of bike