34-PDSIT-2 Carb idle Speed screw vibrates and closes

[Pabloako]

I finally got around to doing this, after konking out at traffic lights and roundabouts and having to jump out into the traffic with a screw driver.  At least I got a few laughs from people behind me. 

I have replaced the O-ring and a simple 5mm "petrol safe" O-Ring from Supercheap. It is all nice and snug again and doesn't move.