Spark lead problems

**thealmightytaco** · 19th November 2005, 18:19

Workin' on the NSR today, she was suddenly running with half power, and sure enough the bottom cylinder wasn't firing. Then with the lead all but pulled off it started firing. Take the lead right off, doesn't go of course, lead with the rubber edge just resting on the end of the plug, it goes perfect, then with plug pressed right on, nuthin'.
I'm thinking I might be losing the spark through some bizarre short circuit that may be fixable so thought I'd post. If anyone knows of how to fix this phenomenom please let me know. Or just tell me to buy a new one you rich bastards. No one out there with a spare lead for an MC16 NSR? Or compatible.

**SixPackBack** · 19th November 2005, 18:22

Check the central diode resitor, if its not that try the low voltage flux capacitor. you'll need a workshop manual to find them

**Motu** · 19th November 2005, 18:30

It's just a fouled plug - you are creating a ''booster gap'' which increases the power of the spark crossing the plug gap.Fit a new plug,cleaned ones don't last long in a 2 stroke.

**thealmightytaco** · 19th November 2005, 19:15

Aha!! I knew it'd be some daft thing like that, cheers Motu. I'm guessing the system ups the current when it feels the spark not getting through? so the fouled plug then works again for a bit? Or sumpin', bridgin' the gap, etc?

But anyway, new plugs it is, cheers Motu.

**F5 Dave** · 21st November 2005, 10:06

Good idea to check the plug cap as well, they contain a resistor & the vibration kills them from time to time. Just wind it off & measure, should be between 5-7Kohm using a $15 multi tester from Dicky Smit or whoever.

But yeah once a plug fouls then it is usually a throw away.