what I'm about to tell you must remain between us, no sniggering, no whispering behind my back.
I pulled the carby off and cleaned out the govenor orifice, I think it was clear anyway, then took the carby apart. I pondered on poppet valves for a while and decided that the carby that I used last year had the 2 position valve and at the time I swapped it for the one that was on the mower I I was working on...the 3 position one.
I thought today that maybe I should use the poppet that was originally in the carby...the 2 position.Did that, then took the diaphragm cap off and deemed that the diaphragm was good and after a clean up started to put it together. I then realised that I couldn't find the locking plate for the diaphragm. Thinking a magpie had pinched it I went to find the other one I knew I had and found 2 in a plastic tray in the shed...I've only ever had 2 of them apart.
Yup been running it since last September without that plate on the diaphragm! It started right up with the new spark plug and although not much response with the thottle control worked well...untill the fuel pipe came off the front plate. Oh well!
Danny