Alright fellas this is what is going on with this mower of mine.
I replaced the plus again (just in case in case).the carby got a carefull clean and inspection. Valves are right still.
I ran it from cold and got about 20 minutes of grass cutting done before it started the rough running and spluttering.
I throttled back to an idle and ran it for a couple of minutes and then on throttling back up to running speed, it coughed, missed and belched a load of black smoke.
I took out the right hand side plug and took a compression reading of 95psi. Replaced it and took out the left side. The Mower wouldn't start and a compression reading taken off the starter motor turning it over read 165 psi.
It looks as though the head gasket is going to be the culprit.
Time to clear a floor space and see how this thing comes apart.
