Topic: K0 carb Q?

[Don R]

 I've been having occasional carb fuel overflows on my cb750 K0, The petcock is clean inside and the tank isn't rusty, I added inline filters just in case. I've removed the float valves and flushed the carbs in the past.
 Anyway I do have foam floats in the carbs and I'm wondering if they could be hanging up inside. Most of the brass floats I have are junk, I'm not sure if brass ones are even available but would be willing to buy them if that's the issue. I've replaced float valves but to be honest I can't remember which bikes other than the F that I sold. I'm about ready to pull the pin and start throwing parts at it.

[evanphi]

bowl gaskets might be catching them inside?

[Johnie]

Don I had that same issue and a float was catching on the inside of the bowl. Just gently squeezed them all in a bit for clearance and have been good since. I hope it is that easy for you.

[70CB750]

I had the problem with Dorothy, cured it by getting kits and replacing all the little pieces.

[754]

Check the floats for parallel. To each other, AND the pivot bracket..
 I caught one in my (carbon rack from hell ).. And it seemed to be dragging against a post.

[Don R]

 Thanks for the tips. I will check each one, it seems to be worse after sitting on the side stand. The Hot Rod 836 needs to get out on the highway.

[harisuluv]

Most likely just worn float valves and seats, but it could be any number of things including but not limited to:

-incorrect float height
-correct float height but bent floats
-crack in overflow drain tube
-debris in fuel system preventing proer seal/cut-off
-wear in the float tang or a "dimple" causing the float to seat in that spot to "jam"
-leaks in the float (only brass type) or large pieces of the synthetic foam missing

Since you swapped floats to the synthetic type (that's ok--they are plain superior) where did you get them from?  I pointed out to another member that not all floats are the same.  Turns out I was right and he did in fact have cb500/550 floats which he thought were the same as cb750 floats (they aren't, the cb550 floats are wider and can catch).  Here are pictures that I posted in that thread.

[Don R]

 I have a good clean tank and filters in the lines, I removed the floats from another set of 750 carbs, I did check the float level a couple times using the clear tube method. The dimple or wear is possible or a float being bent.
 It is a reoccuring deal so somethings up, These carbs have 15K or so miles, they came on this bike but with a non original motor.  Next I'll determine which carb it is, if it's more than one then it's time to do it all.