Just changed my 1300 xflow for a 1600 xflow. The 1300 ticked over and ran fine with no problems and I've used the same distributor and carb for the 1600 but when I blip the throttle it dies. I know it could many things but is there anything obvious that's different between the engines (apart from size!!).

jet sizes will need changing , has the ignition timing been set correctly? have the valve clearances been set , too tight will cause all sorts of running problems. Air leak?

Wrong Carb
if you had a twin choke Webber it will have been a 32 dgv
a 1600 will need to be a 32/36 which has larger venturies.

Thanks for the replies. Ignition timing has been set at 10 BTDC using a strobe without the vacuum attached. Hope that's right. Valve clearances were set, the engine run and re-set so they should be OK. Not sure about an air leak. The original carb is a single choke but I have a 32/36 which I was intending on fitting once I'd got the engine in and running. Presumably I need to fit this carb to get it performing correctly.

Have you checked the accelerator pump is actually squirting?

Accelerator pump is working. However, I've changed to carb to the 32/36 but it won't run at all now. Accelerator pump is working. Just have to keep trying.