I'm doing a complete ignition "replacement parts party" tomorrow, as my parts in that regard are all quite old, and I've recently seen symptoms that a change is indicated. I'm going to replace the plugs, the coils, and the HT lines. I got some bog standard NGK BKR6E .8mm gap plugs from the store today, and will put them in tomorrow. However, I also ordered a set of
Beru Ultra X plugs for $6/plug from Kingsborne.
http://www.kingsborne.com/sparkplugs.htm You need the
UXF79 (normal heat range) or
UXF56 (one step colder heat range) for an M100. Seemingly these are not too hard to get hold of worldwide, even on tiny islands in the North Sea.
I'll post an update in a week or two regarding whether they (
UXF79) make a noticable difference.
PS - Beru Ultra X are now the "premium" plug Kingsborne offers, and they no longer sell the TorqueMasters. "
Robbie the Robot" also advocates & sells the same Beru plugs as a "performance" plug, but they are $10 per plug from him.
Strive for perfection in everything. (given time)
Take the best that exists & make it better. (given inclination)
If it doesn't exist, create it. (God did)
Ignore what I say. (good advice)