Im going to buy a new spark plug for my 1992 kx250 that im about to get back on the road.

The NKG website says the correct plug is a R6252E-9 but after looking at online motorbike shops most say an iridium BR8EIX plug will fit, and one website says a BR9EIX will fit.

Can anyone tell me if im ok using a BR8EIX as that seems to be the one thats listed mostly for my bike on websites, or am i best checking the jetting of the bike first?

Thanks

Do yourself a favour and don't wast money on those iridium plugs in a 2 stroke, just run a BR9ES. We have found they don't foul as easy if your not on the pipe all the time.

The 9 is a cooler heat range. Depending on the conditions, you can run a 7, 8 or 9. And don't waste your money on EIX, BR*ES works just at well at a fraction of the price.

Thanks for the reply fair enough I wont bother with the iridium plugs im happy to use a BR9ES but what about the R6252E-9 which is what NGK recommend for the bike?

br8es (.)(.)

People have different views on what to use then!

My bike is road registered so will mainly be used on the road, around half an hour each time.

Although i dont want it high revving alot i guess thats where it will spend alot of those half an hour sessions, other than that it will be used once or twice a month as a toy off road nothing too heavy.

So what do we reckon then BR8ES or BR9ES?

Thanks

fix said:

No, we are all saying to use a BR_ES, not the EIX. The number is the heat range, so use whateever is stock if you don't know. They're cheap enough so you could try a 8 then a 9 and see what results you get on plug readings.

Jeekinz said:

I mean some people have different idea on what heat plug to use thats all.

I ordered a BR8ES off ebay and then had to get a couple of bits from Kawasaki and I mentioned about spark plugs, the guy said the BR8ES is crap and I should be using a BR8EG. So I stupidly ordered a BR8EG as an extra, oh well I guess ill use both of them in the end.

I dont claim to be a spark plug expert --

but it look like the original number plug R6252E-9 is a "9" heat range. There is also a R6252E-8 and a R6252E-105 with the 8 being hotter and the 105 being colder, the 9 is in the middle. I think your BR8ES is a fine starting point, maybe one heat range cool, but for your type of riding, that might be a good thing!

All the plugs we are talking about here are 14mm, 3/4 inch reach, 13/16 hex.

bottom left of first page of this PDF ---
NGK Spark plug specs

If you are wanting information about spark plugs, heat ranges, etc, this is a MUST READ.
NGK Spark plugs tech
Watch the video on page 2.

The FAQ's here are also helpful -
http://www.sparkplugs.com/faqmain.asp

In the end, you are going to end up inspecting your plugs several times and making your own decision based on your riding style, jet adjustments, etc.

One more important concept --

the air-fuel ratio - aka rich or lean controls the overall combustion and cylinder temperatures. The spark plug heat range controls the temperature of the spark plug tip. A hotter ( leaner ) burning motor will also cause the tip of the spark plug to be warmer, you can put in a cooler plug, to keep the spark plug tip at the same operating temperature as a cooler plug allows the spark plug itself to conduct more heat away from the tip of the plug.

An 8EG just has a somewhat higher quality electrode. Not really stupid at all.

bmcd308 said:

Ive read a few posts about the difference and most people seem to think theres not much if any performance difference between the two plugs, though i guess there must be enough difference for ngk to bother making both plugs

From - http://www.sparkplug...kw=Iridium&pt=1



Iridium is a precious metal that is 6 times harder and 8 times stronger than platinum, it has a 1,200 degree (F) higher melting point than platinum and conducts electricity better. This makes it possible to create the finest wire center electrode ever. Prior till now, spark plug manufacturers have favored platinum for their long life or performance spark plugs due to its high melting point. Also, the technology did not exist to machine and bond iridium on a spark plug electrode (at least in a cost effective manner). Champion spark plugs have produced iridium industrial and aviation spark plugs since the 1960's, but they still sell for over a hundred dollars per plug. Just now is the technology cost effective to use iridium in a spark plug for automotive applications. The strength, hardness and high melting point of iridium makes it very well suited for a fine wire plug. The primary iridium plug manufacturers at this time are Denso with a 0.4mm center electrode, while Champion and NGK have 0.7mm center electrodes. These are the best performance plugs on the market for traditional automotive use and many racing applications. Autolite has introduced an iridium-enhanced plug (the iridium content is too low to call it an iridium plug) we do not consider this in the same class as Denso, NGK or Champion.


So yes, there may be some advantage to Iridium plugs and if you want to use them feel free. I dont run my bike that hot. If you are racing and ride it pegged out in the sand, with lean fuel conditions, etc, then they make more of a difference. Face it -- most of us in this 2-stroke forum are not those sort of riders. If you are, then run the Iridium plugs. I happen to have one in my bike because I did not do research before spending the $$. My spare is a BR8ES. I do carb adjustments with BR8ES and if my BR8EIX ever burns up, I am not spending the $$$ for a new one.

Thanks for all the help, a short answer is im unlikely to see much difference in performance between the plugs as the bike isnt raced.

Ill use both plugs then next time buy an ES plug.