Some time back I'd bought some Champion N5c spark plugs for my 1960 model 50, because they were in a table of spark plugs for british bikes that I'd found online..
I recently noticed that there is a similar table on the NOC website, but has a different value (N4c) for the model 50, which i've now bought and fitted (not yet seriously used, other than starting it and letting it warm up).
I also see references to using a Champion N5 / KLG FE80 and equivalents in period maintenance books (Haycraft and Garrat), so now i'm confused ;-)
I'm wondering what effects I might have noticed with the N5c? I never thought it was running quite 100% correctly with it..
Stick with it.
I have been running N5s in model 50s and ES2s. Never had a problem with them.
Paul
Model 50 Plug: Dross alert
I totally agree with Paul. Thousands of miles on the same N5c and still going strong.
Save the N4 for your 650ss.
thanks
for the feedback :-)
The N4 plugs are a bit more likely to foul up if you are just fidling with the bike . Some plugs of current manufacture appear to fail if allowed to soot up, and dont respond to cleaning like they used to .its called progress !!!.