Originally Posted by
ffkiwi
.........The single component that causes more grief than anything is the very small black rubber gasket (like a tiny O-ring) that seals between the cast backplate and the central induction tube in the tank-if this is not seated, frayed, or damaged it will really spoil your day when it comes to getting consistent running. Definitely #1 for replacing in any overhaul. They come in the Babe Bee gasket/overhaul kits or you can buy them separately.
You will also need to check the fit of the red Kavan tank extension fittings to ensure it seals OK-the plastic may have warped over the years....
ChrisM
'ffkiwi'
Thumbs up on the venturi gasket.
If you want to use the Kavan Tank Extender, you'll need two venturi gaskets. The Extender came with a tube necessary to to extend the venturi tube from the existing tank to the backplate. Many of these extenders had a reputation for leaking and being difficult to get to seal well. Although you'll get a longer run time with the current tank, my inclination would be to remove the extender until you can get the engine up and running. Being plastic, it may well have age cracks and could even crumble while replacing parts.
EX Models here in the US will also have rebuild kits.