Im looking for high performance racing spark plug for KLX 250sf, and is it true I also need to change the wire that connects to it if i change from stock to a high performance? My overall benefits ?

 

NGK is probably gonna be yer best bet. ALL the manufactures use them, atleast all the jap companies do. Its like apple pie and beer here in the states haha. I've always ran NGK's. Plus we sell them haha

 

Why put a high performance race plug on this bike? Really not gonna give you any extra hp. I use Iridium, but just because it's supposed to last longer.
Just my opinion.

 

+1 on Iridium. 15000 km and hasn't missed a beat.

 

NipponDenso Iridium.

 

I've just ordered NGK Iridium from ebay ( i don't have time for shopping :/)

 

I use a BRISK PREMIUM MULTI-SPARK PLUG (AR12ZS). Strange looking plug that I got on ebay ( put in a silly bid & won). They normally go for $15+ which is crazy money for a plug! Bike runs well with it, I have to say

Unless you get one of these cheap or free, go for the IRIDIUM plug!

 

I just use the regular NGK plugs. In my experiance with carbed bikes is that the plug will usually foul out long before it gets worn out so the Iridium is pointless. Even on FI bikes, unless you are running stock fuel mapping you will probably foul out the plug eventually as well.

Just my .02.

 

Iridium plugs are nice, the standard ones work too, and are cheaper. If your four stroke fouls plugs something is not right.

 

Dude, the last thing in the world the stock SF needs is a "high performance racing spark plug".

If you truly want some performance increases, get yourself an aftermarket pipe, less restrictive air intake and a jet change.