I know this is a hoary old subject but...last year after reading Norm K's fix for the plastic carbies and deciding it was out of my skill level, I got the pictured mower running at one speed (a bit fast) with no throttle control whatsoever.
Anyway it was usable although using a bit too much fuel. It stopped dead the other day while I was emptying the catcher, no cough or splutter just cut out. I determined no spark so put a brand new(ish) CJ8 plug in. It starts but immediately continues to rev to the point of self destruction if not shut down.
I remembered afterwards that I had tried this same plug last year and the same thing happened and had used the plug that died the other day. This plug was new from Mitre10 last September and has only been used to start the mower a couple of times with the above result! I can't understand why it would run so differently just because of the plug. Any ideas appreciated.
