Spark Plug and Points Questions

I found a posting by Fred about plug temperature to be quite helpful as I've been playing around with plugs. However, I felt like an idiot today when my moped kept dying at idle and I cleaned the carb without success. Just for the heck of it, I put in a new plug and now it runs like a champ. I guess it needed it. While I was at it, I noticed that the points were adjusted to .020" or greater and the manual for my bike calls for .015" so I changed that, too. Here are some questions. By having a point gap that much larger, what is the effect on timing? Is it harmful? Also, how often do you change your spark plug? Finally, I'd be interested in knowing what plug brand and type people use with their mopeds. Although I'm running plugs one step colder than the manual calls for, here is what I use:

Vespa Ciao NGK B6HS

Vespa Bravo Champion L86C

Vespa Grande NGK B6HS

Thanks in advance,


Re: Spark Plug and Points Questions

most of us in the moped army (if not all, at least in kzoo) run bosch platinum 4214 (it's same as champion L86 series). they are the best. hands down. i use nothing but.

Re: Points Questions

In answer to your points question, it's not the gap but when in relation to the flywheel/ piston position ( degrees before top dead center ) that the points start to open that is important. The duration that the points stay open, expressed in degrees ( in relation to the flywheel, a circle with 360 degrees ) and known as the dwell angle, is not that important in a two cycle, single cylinder engine.

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