Sorry hit wrong button. I've got a 1600 xflow. It had a single barrel Weber but it was too small for the engine. Ive fitted a secondhand 32/36 Weber. Just won't start. It started fine with the single barrel Weber. I appreciate it might not be perfect but I thought it should at least start. I know it's a long shot as there could be a dozen reasons why but perhaps there's something Obvious I've overlooked.

Was the 3236 known to be working before hand?

When you say it won't start, does it even try, is cheek getting through the carb?

If it's been sat a while the jets are possibly blocked.

The 3236 is dead easy to strip, clean and overhaul with new gaskets etc. Lots of guides online on how to do it and parts can be had off eBay or from Burton Power.

Got it going. Ran out of petrol and then realised that the petrol had been standing in the tank for months!! New, clean petrol and it started after a bit of tinkering with the timing. Thanks for all your help.