Mikuni TMR 32 MJN Yoshi

[Don_Karlos]

Hi,
I'm currently fiddling with my CB1 '79 and Mikuni TMR 32 MJN from Japan (Yoshimura). The carbs are new out of the box. My Bike has 6000 mls on the odo and it ran after a cleaning job on the stock carbs pretty well. Now, after the winter I had problems with not running cylinders and very hard starting. Since I had the Mikuni from another project I thought "less parts, less pain" and putted them on the bike. Surprisingly after opening the new Pingel petcock and pumping two times with the throttle it started immediately and ran on 5 cylinders. Cylinder 6 is not running. Since I have open intakes (original Mikuni) I was able to put four fingers on the opening to reduce air flow - and cylinder 6 came to live. But it is only occasionally firing when I reduce air flow and increase vacuum through that. Is here anbody who has an idea what is wrong with carb 6? Idle system clogged. Anything miss-adjusted? Any tricks?
A video with bike running can be watched here:

http://youtu.be/61CoTAaKiKA

Thanks in advance
Karl