1972 CB500 Carbs/Piston

[rkleen]

Hi!
I have a 1972 CB500 that has been rebuilt, among other things, the inside of the carbs (jets, needles, slow needles, etc) but still leak (2 carbs) from the recuperation hoses.
I open the carbs, clean them, adjust the height of the floaters at 22 mm, and still they get stuck sometimes. They dont move freely.

Also, and I think it could be a problem related to the carbs, I believe 2 pistons are not working right or receiving fuel, because when the bike is running, it is not smooth and two exhaust are getting yellow but the other two are cold...

what do you think?

 

[malvarez909]

hey there, just out of experience, i think that you simply have to just make sure they are really really really! clean! Also, make sure that the positioning of both pistons and slides are in the correct position. Sometimes even a little play will mess up everything. I'm having trouble right now with my carbs from a 71 cb500. It's all adjustment problems, heres a link of the manual just in case, helped me out. go on the forum and find the link,it should work no problem

http://www.dotheton.com/forum/index.php?topic=11077.0

If your carbs are leaking, make sure your gaskets are new, also make sure that the hoses for the gas are in good condition, even little cracks on the hoses convert to leaks. Make sure that the air adjustment screws are about 1 1/8 to 1 1/2 turns out, depending whether you are running pods or just stock air box. Same with an aftermarket exhaust.
In this case, you might have to main jet (size up or down). stock i know is 100# for main and 40# for slow.
Also i was reading when you put the pistons back in to the housing, make sure that the cutaway section faces the choke valve direction. Everything on these carbs are minor tweaks til perfection, good luck, let me know how it goes.
I need to adjust everything on my carbs, for some reason when i accelerate my throttle the rpms go down and turn off the bike, assuming too much air is coming in or lack of air coming in. I will see, good luck bro!