~~ Ngk - BL6 Spark Plug ~~

butterbean said:

It's a B6L, not a BL6. It's a plug apparently used in Harley Sportsters, as that's what they matched my stock plug to at a motorcycle shop back when I still rode 2 strokes. If the people at Auto Zone told you it wasn't listed, they were either lying, stupid, or typed in bl6 instead of b6l like they should have (did you say BL6 or B6L when you asked? It does make a difference). With NGK's designations, a plug marked 6 is hotter than a plug marked 7, but colder than a plug marked 5. A B6L is not a direct match to the stock plug, because it's hotter but the Chinese don't know that (or whoever made the cross reference list I read doesn't know it?). I ran the B6L in my stock 48cc with 87 octane, blew the rings in it. It seems weaker, but what's actually happening is the hotter spark is igniting the mix faster, causing the engine to lose power because pre-ignited mix doesn't burn at the correct time. The mix burns before it's compressed, and when it does compress there isn't as much left to burn. A B6L would be a great plug for an engine with a high compression head running 90 octane or above, but it's absolutely no good for a stock engine running low octane.

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