#1 not as hot as 2,3,&4

[chingloy]

the bike is running great. i put new plugs, new air and fuel filter, when i checked the heat of the exhuast i noticed cylinder #1 was not as hot as #'s 2,3,4. carb was also synchronized. what do you guys thinks? it runs great, no problem what so ever. runs the whole powerband up to 13,500rpm no problem. runs smoothly. i have a beet full exhaust on it

[clarkdw]

Dirty idle jet. Will show up most obvious when you first start the bike and it is idling. It can run great through the rest of the rev range. The holes are soooooo tiny that they plug easily.

[chingloy]

thanks clark, nice to hear pistons/rings are not shot! how do i get to it?

[91cb-1]

Rip the carbs out and give them a really thourough cleaning using a ultra sonic cleaner if you can get your hands on one

[schedMas]

Had a similar problem with my CB1, #1 is not as hot as 2, 3 and 4 in idle but runs great on high rev.  I had the carbs cleaned the heat on #1 improved slightly on idle.  Took out the air cleaner assembly and started the engine, placed my palm over carb1 and its not sucking on idle compared to 2, 3 and 4 which when i covered the carbs with my palm the engine chokes.  Plugs are ok, as well as plug cables. Its like the butterfly on #1 is totally closed in idle.  what do you think guys?

[Samuichris]

When you put the carbs back in make sure you get them balanced correctly.

[schedMas]

I'll do that and have the air and fuel filters replaced as well, thanks!