Initially it would run fine then after a while if you did vigorous forward and back motion it would run unevenly.

Now it won't start. Has spark and fuel is getting to the combustion chamber. It is not flooded, I have left it for days then tried again.

I know quite a bit about car engines and it is like the timing is out. Sometimes it backfires out of either the carb or the exhaust. But I don't see how the timing can be out with such a simple magneto/permanent magnet arrangement?

Any ideas?

Mark, July 2008

Have you checked the flywheel key way hasnt broken and allowed timing to be out?

david clayton, September 2008

Check to see if flywheel key has sheared

Modge, July 2008

Sound like the carb diaphragm. If it also emits puffs of black smoke with irregular idling then that's the case. May well be something as simple as the plug- try that first it's easier and quicker to change.

pleasant, July 2008

1s t thing i do is to replace the carb diaphram,costs little fixes lots(they rot if u leave fuel inem over winter)that said,check carb to head flange/gasket security possible the gaskets gone/loose letting in unmetered air.

caine, July 2008