If it's cutting out at or close to tickover don't strip your Carb! They all do that! It's an XBR thing. There were some modified valve clearences that were supposed to help. Upping the tickover a little also helps.
PS - if you've left it standing for a few weeks and you find there is no compression, don't panic and pull the head off ( many have!), cos thats an XBR thing too. I don't know why they do it, but if you keep kicking it over compression will eventually return and it'll run right as rain.
PPS - If you ever have to take the head off and find a hairline crack between the plug hole and a valve seat also don't panic - they all do that too and it doesn't seem to make any difference.
