Well. I didnt get time to pull the carby off as I was working on a few other units on the weekend.

I did however replace the air filter as the current one was just about blocked up solid with dirt. I am surprised the engine started at all. I'll put a photo up tonight.

So for now the mower is running so close to perfect its not funny. I will however be taking the carby off as instructed and giving the mower a good once over. I'll also check the valve clearances this week to make sure everything is ok.
Grumpy, Joe and Bigted, I appreciate the pointers as always.
I do find it strange how people can throw a good unit in the bin.