"It seems a KLG F80 is the correct item and I'm guessing that F70 and F75 are hotter versions of the F80? Is this right?"
My M20 manual quotes KLG F70 ?
Very interesting to read that article Ian. I've heard this before that the modern insulators can't cope with being coated with neat petrol. I've just experienced it myself whilst trying to start John A's 720! As soon as a plug got wet....No spark at all and little chance of reviving that plug. 3rd plug 3rd time lucky. Ron
That article is on the Green Sparkplug co website under "Technical" "New plugs".
I also think modern NGK plugs don't work well with magnetos. I then tried the same new plug on a bike with electronic ignition and it has bright blue spark, and no spark on the mag. Tried an old Lodge plug on the mag and it worked ok. I wondered if there was too much resistance.?
