cylinder #2 does not fire? Cold exhaust.

Hi guys, I've been trying to find out why exhaust no. 2 is cold to the touch all others are plenty hot. I noticed it after I accidentally touched my exhaust pipe.

While riding, the engine still runs smooth after it's warmed up.

The spark plug is OK, I've switched the plug with #1 and #1 still gets hot.

I think the carb is the problem, I let my bike idle w/choke and my exhaust no. 2 gets hot, but with no choke my exhaust no. 2 starts to get cold.

Last week I had off the carbs of the bike, they all seemed fine and had no vacuum leaks. I cleaned them but I still have the problem.

Any guesses?

 

I had this issue when my float fuel levels were out of spec. The one cylinder that wouldn't fire when cold was a few millimetres too low. If those are all in spec, you may have some debris in the pilot jet/passage, any amount of gunk in there is going to cause issues.

 

Doesn't the pilot fuel system supply most of the fuel up to about 20 mph the the main system kicks in ?

 

yes up to 2k to 3 k rpm you run off of pilots.

could be air jets are reversed mixture screw needs a little more adjusting sync off for that carb or pilot jet circuit is dirty/bad parts mixed up jets

 

I had a similar problem a while back and it was a loose connection in the spark plug boot