Spark plug question? 2003 KX250

[svttodd]

I know, there are a million threads about spark plugs, but I haven't found an answer for my problem yet. I have a 2003 Kawasaki KX250 with low hours, and great compression, a Pro Circuit pipe. It was running great, never fouling a plug, not too rich or lean. I changed the plug just for the sake of putting a fresh one in it, and now it wants to bog just a little on the slow tight trails. Nothing else was changed, only the plug.

The bike had a NGK B8EV in it and the plug looked perfect when I tool it out. I replaced it with a NGK B8EGV, which makes a slight bogging effect, but the plug looks good upon inspection (just a tad more black looking than the other plug, but it still looks withing the 'good' rating). The book reccommends a BR8EIX, and two buddys reccommend a BR8ES (has the fat center electrode). I cannot find a BR8EIX locally, does it have the thin center electrode (the thinner one seems to be a better idea)? Anyway, what plug is good for this bike? Would a simple plug change to a simular looking plug make the bike bog slightly? Thanks. -Todd

 

[CJG]

svttodd,
I think you may just have a bad plug. It's possible you could be getting some interference due to using a non-resistor plug, but that's highly unlikely- especially considering that the plug you were using before was also a non-resistor plug. I have used the resistor version(BR8EGV) of the same plug before with good results. Right now I'm using the BR8EG(cheap and easy to find) and have had no problems.

Yes, the BR8EIX does have the smaller(iridium platinum) electrode. According to NGK, the purpose of the thinner electrode is to reduce the voltage requirements and extend ignition system life. For more info on what these letters mean go to http://www.ngksparkplugs.com/techinfo/spark_plugs/partnumberkey.pdf

 

[GhostRider32]

I have the same bike and I read in the owners manual that if you want to go to a BR7 plug, it was ok. I've been using the BR7 version for a year now with no problems.

 

[Britt Boyette]

I run the BR7 and BR8's depending on where I'm riding and weather conditions without any problems. If you want a BR8EIX, you might have better luck buying it at a Auto Zone or sometimes Wal Mart. Plus, at $7.00 each retail, you'll probally get a better price break. They do seem to hold up better and last a bit longer so figure that into your overall cost.

 

[NM_KDX200]

I use the BR8EIX in both my bikes and am VERY happy with them. I order them from rockymountainatv. Spark plugs last forever for me- my KDX ran the same exact plug for 2 years and I only changed it 'cause I was doing a top end (routine maint, not grenaded).

ES in both bikes will bog a little, EIX runs crisp as a cool cucumber.

 

[svttodd]

Thanks everyone. I found a BR8EIX and a BR7EIX since the first post. I am goin to try the 7 first. The original BR8EIX was like new when I took it out, I just thought that I was doing a good thing by putting a new one in after over a year on the same plug. Actually, the plug looked perfect, and it probably would have lasted a long time. I won't mess with the new one until it looks 'worn'.