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Dave102429
11-15-2004, 11:07 AM
On a 2002 400EX, there's a 5K resistor inside the spark plug cap/boot behind the terminal that the end of the spark plug snaps in. Back when I had my XR250, the hot trick was to replace the resistor with a piece of cooper welding rod of the same size as the resistor. My XR250 ran pretty good and I never had a problem with it. Has anyone tried this trick on a 400EX? What's the purpose of the resistor? Thanks.

motoboy66
11-15-2004, 09:48 PM
never heard of it, but i will try it, I have an old plug cap that I took off because the resistor went out. I'll let you know this weekend when I try it.