1974 Kz400 Left Bank Issue

Recently picked up a 1974 Kz400 custom and am having an issue. The left bank seems to cut in and out while riding at different throttle. It seems to have a louder resonance than the right bank and is not as smooth... Any ideas where to start? Carbs were just rebuilt and jetted by a local motorcycle shop and cleaned out.

Sorry,i have to ask but what exactly do you mean when you say:

The left bank seems to cut in and out

I couldn't imagine your description, sorry.
The carb body, air filter body,air filter pods suction noise???
Have you a performance loss issue?
Some pics of the custom KZ400 will help a lot.

I would talk to the shop that did the work. If they changed the jetting, they should have taken the bike for a test ride to make sure it works.

I know my description was vague. It was late last night and I was tired... sorry for that.

The shop that did the work is a friend who has done work on our bikes for years and unfortunately being a friend takes forever to get stuff some.

Here is the situation: when I fire the bike up the left side sounds raspy and louder than the right side. The right is smooth and doesnt "crack" like the left. As I ride it I can feel in certian throttle positions that the left cylinder is cutting in and out and I can feel it surge a bit when the left side come in and out. I am thinking it may be a carb starving situation as the spark plugs looks the same. Any ideas? I was also told that it may need a bit more back pressure in teh exhaust.

That's rather nice looking, but you have pod filters and after market exhaust which leads me to say all noise and no go, you need a stock air box or a made up one like a couple of the members on here have, CV carbs and pods do not work together and any one that says they do is being economical with the truth, once you have that done see if all valve lash is correct, ignition timing correct, and carb settings are as stock check you have a good 12 volts at the coil/s and new spark plugs, get it running like that and if any thing you may have to come up a size on pilot and main jets and possibly raise the needle slightly if the needle is of the adjustable type

thanks for the information. It does do 70 on the highway no problem but could run a bit smoother... I will switch out ot an air box or K&N and see what happens