Your right it is not for a Weber like what i have fitted. Speedle, it was a square with one of the corners rounded off. I knew it wouldnt just bolt on when i bought it Slim. Had a plan for it.
To make it the right shape and size:
I made a plate that sits nicely in the base, cut a hole the right size in the centre to fit it. To make sure it had a good snug fit, I put some lagging tape round the inside of the hole. Actually fixing it was a bit of a pain. I will post a pic of what i did when i get home.
For the fitting bracket:
Its a small length of 15mm copper tube, squashed in the middle with a hole drilled to accept a bolt for the top of the carb(as this is the only mounting point with a K10). Bent the tube at a 45deg angle, cut a half section of the tube about an inch long and flattened it, bent these back to horizontal with a hole in each to sit over the treads that hold the top cover on. Once the top cover is bolted on it all tightens up so none of it moves at all. Once painted black it looks like it was made for it. O the joys of being an engineer.lol
The carb I bought was Elliot’s old one and it was already set up for a K&N. So I wasn’t too worried about re-jetting. To be honest i got it for the sound, and it does sounds lovely.
If anyone would like to buy these K&N’s for theirs I could make up a guid with lots of pics, if people wanted it that is.
Cheers