One cylinder not burning

[schedMas]

I just got my CB-1 two weeks ago, it has 23T good kms on it, all original.  Been using it to work everyday since, recently i noticed that carb 1 is overflowing, i turned off the fuel tank valve and drained the problem carb, it solved the overflowing problem, but problem is i noticed that cylinder 1 exhaust is not heating up thoroughly compared to the other 3.  I haven"t noticed any change in power though, I checked the plug and cable and is firing well, I havent however checked nor changed the fuel and air filters, i'm thinking of having them replaced and have the carbs cleaned too.  Hope this will do the trick.  Any further advice would be very helpful, thanks in advance guys.

[clarkdw]

Jets in the carb are clogged. One or more pipes cold when you start it is a very common problem with these bikes. Dirty idle jets are almost always the problem. By all means replace the filters, but you will find the problem in the teeny tiny orifices in the carbs.

It very often does not have any effect on high speed running because the main jets are much bigger and do not clog as quickly.

[schedMas]

Thank you so much, I will surely follow that and have the filters replaced and the carbs cleaned asap and also have the oil changed too, what do you think about the plugs, should i also replace all four?

[clarkdw]

If you replace all the plugs you will know that they are good and how many km are on them. Leaving the old ones in always leaves some doubt.

Whenever I buy a vehicle of any sort  I always include the price of freshening everything up because unless the original owner has very detailed records you just don't know what has been done.

[Drewski]

+1 on the pilot jet. Might be worth changing the plug, or even better swapping two plugs over, before removing the carbs.

[schedMas]

I cleaned the carbs and swapped the plug from the problem cylinder (Cylinder 1) to the plug of cylinder 3, blew compressed air on the air filter, it solved the problem, however i should really replace the fuel and air filter and the plugs all together to further condition the engine, thanks for the insights guys