Darryl,
Apologies for coming back again but something that you wrote in your post of 16/2 has caused me to seek confirmation. If you look at my uploaded photo, the tube that I didn't know what to connect to (marked with black tape) and which you said should go to the broken connector on back of carby is the vacuum tube. This vacuum tube goes to a needle size air inake clipped to the cowel.
In your post you said that that tube goes to the decompressor. Again, as you can see from my photo, the tube from my decompressor is currently connected to the side of my carby. This is how it was sold to me but it could well be that the seller has been tinkering and I note that Joe Carroll in his reply also said that the tube from my broken connecter should go to the decompressor.
Could I trouble you to have another look at your Tilta 80 and let me know please.
regards