Spins well, battery is good
Just before it eventually fires up it will cough a bit, then I have to catch it
I’ve had different comments about pressing the throttle, but I still do so
The engine is sound and been on rolling road, the only changes have been E10 fuel and pancake filter, although the latter was fitted before the RR
The choke could be sticking in the fully open position. I had an empi carb that had this problem so every time I wanted to restart it from cold I had to open the engine lid and push the stepped cam back to free it off.
Is it a still on the original carb with automatic choke?
If it is are you allowing the choke to engage before starting the engine?, in order to do this you need to turn the ignition on, 2 warning lights on your dash, press the throttle pedal down to release the choke mechanism and then release it, then turn the key to crank it, if you don't do this it doesnt set the choke.
Hope that helps, if you have aftermarket twin carbs then they usually don't have chokes fitted so can take longer to start from cold.