Freshly rebuilt bike was firing on 4 cylinders, now down to two

[Unstoidable]

Hello


Bike has been off the road for 18 months, finally managed to solve a leaky carb issue and rebuilt the bike. Had a leak on the tank valve, so emptied the tank and put in some fresh petrol when I changed it out.


Bike started, ran on 4 cylinders for a while, and now is down to the left 2? Seems to be running quite rich as well, I can smell the petrol as its running.


Any suggestions? Would very much like to get it back on the road and MOT'd soon, ready for the summer.


Thanks in advance

[BBROWN1664]

if its running on two, the other two will be pumping un-burnt fuel into the exhaust making it seem rich. That's assuming the carbs are not blocked.

Are the coils connected correctly? left hand one (as you sit on teh bike) connected to #1 & #4 and the right hand one connected to #2 & #3?

Does it run on all 4 at higher revs (above 4-5k)?

[Unstoidable]

Coils connected properly, because i've done that before 


I will check when I next go out to it, it ran on all four to start with then number 3 and 4 exhausts were clap cold after 5 minutes

[unfazed]

Are you sure you didn't put plug lead 3 on plug 4 and plug lead 4 on plug 3. Very easily done and looks right, especially if the leads on the tags are missing

[Unstoidable]

All leads have numbers on them still, so all connected up correctly

[unfazed]

When it was idle was it on the side stand the whole time?  If it was the most likely issues is blocked pilot jets