1 exhaust running cooler than others

Any reason one exhaust header would be cooler than the others? Noticeable difference when quickly touching/waving your hand over the pipes. It's cylinder either 2 or 3, the one closer to the center of the engine on the left side, on an '82 YICS 650 Maxim. Bike seems to run normally as is, and it's still firing, bike runs awful with it unplugged, normally with it plugged in. Needs a carb cleaning and sync?

 

With what unplugged, please clarify or elaborate......spark plug I would imagine. A thorough carb cleaning & sync & colortune is always the best solution.......

Do it right the first time and you only have to do it once. But most people take shortcuts ( I am guilty of that as well ) and wind up ripping the carbs back off 2 or 3 times to get it right....

 

Yes sorry about that, with the spark plug for that cylinder unplugged I meant

 

the header pipes are double wall, there might be a leak in the liner pipe letting the outer pipe get hotter. read the plugs for the mixture, if they all look the same it's probably the pipe

 

I've got a cool cylinder as well, #4. I was using an infrared thermometer I got at Costco, so I'm not sure how accurate it is but I am curious what is a normal temp at idle at the header? I do have a carb cleaning on the horizon.

 

the plugs tell the story, there's too many variables for pipe temp to tell you much

 

while you're on the bike cyl #1 is on the left, #4 on the right

 

Yep, yep and yep . . . .
On the plus side, if you take shortcuts you become rather proficient at removing and installing your rack.

 

could be plug is not firing properly (bad plug) or spark plug cap is failing bad connection.
first thing would be to swap plug out to another cylinder and see if the problem follows the plug or just swap in a new plug if you have one.
make sure the screw in the cap is tight it is on the inside, if it is an oem cap. there is a slot in the brass inside and could just need to be tightened
ohm out the spark plug wire pair. with caps on. if out of spec then remove caps and ohm out the caps.
trim back the spark plug wire a little on the bad plug wire wire could be corroded

what do your plugs look like? could be you need to adjust the fuel mixture screw.
word of caution it could be your other 3 cylinders are running hotter than supposed to , lean.

plug color is the key

 

I will have to pull the plugs and have a look at them, could it really be all 3 other cylinders running lean? I hope it isn't the plug as I just got brand new ones less than a month ago. Recently it has also had some trouble starting when completely cold, like if it has sat overnight, my guess is gummed up carbs are probably the cause of both problems

 

Carb Cleaning is in order...bite the bullet......yank those carbs and go thru them.......thoroughly......you won't regret it.........but do it once.....trouble starting when cold is a sign of clogged enrichment circuit ( choke )......

 

could be 3 lean one good or just a bad plug , cap
when you pull the plugs move the suspect to another cylinder to see if it follows then suspect spark plug cap and corroded wire end . simple things first
then pull the carbs and dive in to clean them