Another part ID for my Demon

[French demon]

Is this Ball & Ball carb original to my 198ci '71 Demon?

It's not working properly : rough engine RPM at low speed, sometimes dies out in traffic.

No problem at "high" speed (on the road), and with cold engine, the automatic choke works fine.

All help will be appreciated
Francois

 

[cudascott]

have you checked to make sure your choke is working properly. If it’s partially closed after warm up it would do what you described.

 

[French demon]

Thank you for this advice, I will check if my choke flap is fully open after warmup.

 

[French demon]

I checked my choke and the flap is totally open when the engine is warm.
So, the problem is elsewhere...