Carburator/fuel issues

[carg3]

Hello everybody.

I have a couple of issues with my 1972 CB750.

1- I only see exhaust gases coming out the pipes from cylinders 3&4. The pipes from cylinders 1&2 get hot (not as hot as 3&4) but I don't see any gases coming from the exhaust.
2- It takes a few seconds for the bike to go back to idle after twisting/releasing the throttle.

Any ideas on what to check? There's spark and I think fuel is going to the carbs, but maybe the fuel hose routing is not correct?

Here are the pictures of the carb and how I'm routing the hoses

 

[Darren G]

Pull plug wire off each cylinder one at a time and see if it is or isn't run on that cylinder. While bike is running you can put you hand over one carb at a time if it bogs down it's most likely running on that cylinder and if it kicks in on that cylinder it wasn't working on that cylinder and I'm not sure about your hose routing