Topic: cb350f float settings?

[johnws6]

so maybe im overlooking this but ive been searching with no luck for about 30 minutes and im tired of looking. but does anyone know the proper height of the floats or have any links to a detailed carb manual

[flybox1]

The book says 21mm, but if you've added aftermarket float valves, you will need to be closer to 24mm.
use the clear tube method to verify fuel level once you set the floats.

[johnws6]

clear tube method? sorry if that's a dumb question

[flybox1]

clear tube method? sorry if that's a dumb question

Not at all...Its a visual test to see where your floats stop and hold the fuel level. 
verify your floats are 21mm, and then perform the test.  adjust as needed to attain the desired fuel level.
Do this on the bench with an auxiliary fuel source, to save from installing/removing carbs from bike multiple times.
For your 350F's carbs, just knife-taper some clear tube to twist into the drain screw hole to perform the test.  Do one carb at a time.

[johnws6]

thanks a million, I have it cranked (it hasn't run in my life time 24 years) but the front caliper is locked up, still not getting it to move yet. and it wont run without the choke, but im running leaking old carbs so I have a lot of parts on the way. and I finally got a broken spark plug out, im sure they didn't put anti seize on them since I found one that didn't even belong and was only in about 3 threads (thank goodness they didn't tighten down further and mess up the threads. anyway I might just make a restoration thread on this bike

[flybox1]

please do make a thread. 
You'll get plenty of help here.  those are fun little bikes 

[johnws6]

I have 2 carbs that keep overflowing. at this point I think there are only 2 possible causes. just replaced all the parts and it runs great with the gas tank shut off, I think ive got it dialed in pretty well. but either the floats (that look good) are bad. or the new needles (that aren't rubber tipped) aren't sealing. anyone have any thoughts?

[knowsnothing]

The floats are probably fine, but to check the ones in question, take them out and drop them in a cup of gas for a little while.  If they float, they are good.  With these later floats, the material they are made of inherently floats so you don't have to worry about them getting holes like the earlier brass ones. 

If you are sure the float levels are set correctly, swap the float needles.  If the overflow follows the needles, they may be the issue. 

On my 350f, i had an intermittent over flow issue on 3 of the carbs that didn't seem to follow a pattern.  Turns out there was a small indentation on the float tang where it made contact with the top of the float needle.  They would get hung up every so often causing the overflow.  To remedy this, i took the floats out and careful sanded the indentation out of the tangs.  So far that seems to have worked. 

[flybox1]

at this point i'd replace the needle AND its seat.
they are a pair.  matched tapers. 
if you just buy a new needle, with a little toothpaste, lap in the new needle
sucks that they cant make 350/400 needles w the viton tip 

http://4into1.com/replica-keihin-float-needle-valve-assembly-16011-329-004/

[johnws6]

at this point i'd replace the needle AND its seat.
they are a pair.  matched tapers. 
if you just buy a new needle, with a little toothpaste, lap in the new needle
sucks that they cant make 350/400 needles w the viton tip 

http://4into1.com/replica-keihin-float-needle-valve-assembly-16011-329-004/

I have replaced both, I rebuilt the whole carbs with new stuff. but its still not sealing and the float levels don't really come into play (even though I did set them) because if you block off the drains fuel will come out the ports of the carbs

[dbbrian350F]

please do make a thread. 
You'll get plenty of help here.  those are fun little bikes 

This thread will help me too. I have my carbs to clean also.

My front brake was stuck, so I loosened the two bolts on the caliper so at least be able to roll the bike out and work on it. The caliper will need a rebuild anyway.

[flybox1]

If your floats are set correctly, and your float valves and seats are new, fuel should shut off.
Revisit the float height, lap the valves in the seats, and clear tube test each bowl.
You've missed something.....

[johnws6]

If your floats are set correctly, and your float valves and seats are new, fuel should shut off.
Revisit the float height, lap the valves in the seats, and clear tube test each bowl.
You've missed something.....

you have to be right. im really thinking the new needles aren't right because ive had them  on and off at least a dozen times and I cant find a clear problem. the only thing I see left is something wrong with the new jets and seats

[Bodi]

Confirm the floats are installed the right way up. On 350/400 carbs, the right way looks wrong.

[carnivorous chicken]

The floats are probably fine, but to check the ones in question, take them out and drop them in a cup of gas for a little while.  If they float, they are good.  With these later floats, the material they are made of inherently floats so you don't have to worry about them getting holes like the earlier brass ones. 

If you are sure the float levels are set correctly, swap the float needles.  If the overflow follows the needles, they may be the issue. 

On my 350f, i had an intermittent over flow issue on 3 of the carbs that didn't seem to follow a pattern.  Turns out there was a small indentation on the float tang where it made contact with the top of the float needle.  They would get hung up every so often causing the overflow.  To remedy this, i took the floats out and careful sanded the indentation out of the tangs.  So far that seems to have worked.

Check this... And sometimes if the tangs are at a weird angle or have been adjusted one or two too many times, they sit at a kind of weird angle and the needle can get hung up on it, preventing the float from rising.