Newb Question What does this mean and is it significant?

[xs400neophite]

I noticed the pipe on the right was bluer than the other and later, when I cleaned the carbs again to check for tank debri, I noticed these rings in the right side carberator throat.I was wondering what does this mean and is it significant?
The bike had been sitting garaged since 1983 and I just cleaned her tank tank and Carbs, changed air filters,new sparks,carb holders ect. She fired up on the fourth try and idled once she heated up.I rode her up and down the street a couple of times and started her a few times. Havnt checked gap,timing nor tuned the carbs yet.Im not a great mechanic but we all started somewhere right?

pic on the left is the rightside carb, pic on the right is the lefthand carb. Is that Normal?

 

[bcware]

Are you the original owner? Have you ever used starter fluid? I have never seen any burn marks inside my carbs, but I would think there would need to be a lot of excess fuel in there for it to happen. Maybe you're flooding a little on one side?

 

[xs400neophite]

Nah.. not original owner...2nd owner. I dont know if he used starter fluid or not. So enuf to say that is NOT normal aye? Ok good to know. I will read and re-read my Haynes manual on fuel,carberation and electrical. Hey I do know the first time I started her,the throttle cable was not connected and she idled like puhpuhpuhpuhpuh....perfect! So I connected the throttle cable but it wasnt adjusted right and she was almost wide open for like a second or two when I started her... until I killed it. I freaked out bcs it was only her second start since '83 and it was a little much...blew out the rust from the baffles though. Adjusted the throttle cable and restarted her and she ran perfect!! Cool bc... I see your a regular on here and I liked the tube and bottle trick for brakes.

 

[Shaun Chandler]

I have two full sets of carbs both have those dark burn marks aswell. I'm ummm mabey the 5th owner of one and no cluse on the other cause I can't even trace the ownership

 

[bcware]

My guess would be starter fluid exploding out of the carbs; small fires happen some times If it runs perfect it is very unlikely you're flooding at all. Someone probably had trouble on a cold day.

 

[xschris]

It happens from a back fire in the carb. No real issue unless it happens a lot, just clean them and have at it