Sparkplug problem for 03 YZ125

I was just wondering what spark plug i should use in my 2003 YZ125 because i just bought it and i fouled 2 spark plugs in 2 days, im using 50:1 mixture and the plug i have been using is a NGK BR9ES...Any suggestions?

we will need jetting info/ what mix ratio did previos owner use?

previous owner used same ratio....can a bad water pump keep causing these to foul?

Hi there

I would use the BR8ES plus readjuting the jetting. The harder your ride the higher you have to go in jetting. More lugging and slow rpm leaner, those bikes love to be run hard.

Slow riding provokes a lot or spooge IMO

In my YZ250 I get away running a BR10EGV no spooge and running at 48/NP3/185 Airscrew @ 1.75



okay thanks im going to try that out today and see what happens

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