Tomos spark plug - to R or not to R?

Hiya people that know more than me about electrical stuff,

Tomos 2000 Targa and 2004 ST

I have read way too much about spark plugs. The MA Wiki says NGK B6HS for the above bikes but also says BR6HS for CDI ignitions. Myrons says the above bikes have CDIs. NGK website says resistor-type spark plugs should not be used with CDI ignitions as they may affect timing and short themselves out.

WTF??? Do I just need a B6HS (the bike came with one)? Will a BR6HS really be detrimental? All is stock and will be kept stock for the time being.

Thanks in advance,


Re: Tomos spark plug - to R or not to R?

either will work. the R seems to be generally unecessary on tomos cdi

Re: Tomos spark plug - to R or not to R?

Brent Bublitz /

Conventional wisdom says that you need to use resistor plugs or a resistor wire/boot with a CDI ignition to avoid blowing out the CDI box.

Non-resistor plugs should be used for points systems, as they provide a better spark

Your mileage may vary, but if it has a CDI, I would use the R plug. Ignore the NGK site as that's generic info, not model specific.

The resistance in the CDI circuit has to come from some item along the way. Either the wire, or the cap or the plug. The only way I would not use an R plug is if I had a resistor wire or cap on there. Anyone know if the Tomos runs a resistor cap?

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