Thank you for your response.
Your description of the effects of running lean fits this problem exactly.
With the engine running smoothly at low revs I increase the throttle and adjust the mixture screw but it gets to the point where adjusting the screw has no effect and it begins "hunting"...more throttle and it misfires badly and spits back through the carby.
Occasionally when I shut it down it will backfire loudly (which frightens the bejeezes out of the dog).
This engine sat for 4 years or more with fuel in the system.
I have attempted to clean the carby using Nulon Throttle Body & Carby Cleaner.
There was a build up of gum on the needle and seat, the float and most other visible parts of the carby which I have cleaned off.
I have been unable to remove the main jet, it appears to be stuck in place so I have sprayed the cleaning product through it (several times) and blown it out with compressed air.
The problem persists.
Is there a way of removing the main jet without damaging it beyond repair. I'll need to get it out if I have to replace it.
Best regards.
Rob Patterson.
