Hi Grumpy, you are missing something, I didn't leave fuel in it to dry out and leave gum behind. I ran it dry.

Looks like Bruce has hit the nail on the head. I took the muffler off, refitted everything else, hooked up the jumper leads and hit the key. After a few seconds it started to fire and then it caught and ran like a charm. I disconnected the leads and jumped on it and mowed for about 5 minutes without missing a beat. Will pick up a new muffler in the morning.
I don't understand why it did it because it doesn't appear to be blocked but

it works. Thanks heaps for the advice Bruce. I have sent a little something through Paypal, enjoy a beer or two!

Gazza