Triumph Repair: Spitfire Weber 45 black exhaust, weber carburetors, weber carbs

Question
Hi Howard, I have a 1975 Spitfire with a Weber 45 DCOE.
The problem is the exhaust is smelly and it puffs black smoke
so that driving it is unenjoyable, also hard starting.(always has been)
The engine was replaced and the mechanic removed the exhaust recirculation system and plugged up the holes.
Can I adjust the carb to make it run cleaner? or maybe there is some other issue. \any help would be appreciated.

Thanks,

Frank

Answer
Hi Frank,
You can adjust the idle mixture, but if it blows black smoke above idle you need to look at the choke and make sure it is not flooding. If they are ok you may need to change the main jets. You need to get a service manual on Webers to diagnose a rich mixture. Weber carbs never came on Spitfires. Haynes has a service manual on just Weber carburetors.
Howard