Change in recommended spark plugs

[kk4df]

For my 1985 Mariner 8HP, the Selco manual shows using Champion L86 plugs gapped at 0.024. The current Champion reference manual shows using L82 (cooler) plugs gapped at 0.038 for this same engine. I tend to think the current Champion manual should show the correct plug and gap, but I don't understand why such a big difference exists. I'm guessing the Selco values come from the original manufacturer recommendations, and perhaps the change in plugs and gap has to do with the ethanol-based composition of the gasoline sold today? Any ideas?

 

[alcan]

Re: Change in recommended spark plugs

Walter<br />The best bet for an answer to this question is to ask at a certified Merc repair center. They may have service bulletins in regaurds to this issue. Also Champion may have discontinued one plug in favor of another, this happens often.