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Discussion Starter · #1 · (Edited)
Hi All,

As I understand it, the float height for my 3-c carb on my '69 cb350 is 21mm. I set the heights accordingly. When I hooked them to the fuel lines both had fuel coming out of the bottom, through the overflow tube in the carb bowl. That symptom lends me to believe I had set the height incorrectly. I took the carbs apart, watched some videos on how to set the height and did it again. I can't figure out what I'm doing wrong. At 21mm the float is nearly bottoming out. Do I have the right floats for my carbs? (see photo, I included caliper for good measure--pun intended).

Thanks in advance.
 

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When you set the height you are not compressing the spring on the float valve, correct? If you hold it at the right angle you can get a measurement and not have the weight of the float push on the spring.
 

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my memory is a little fuzzy on specifics...somewhere between the 350a carb and the 3D carbs the floats changed from square to round. post pictures of the carbs and the float bowls to see if I can recognize which your carbs need.

here's the spec sheet by the way.
does your serial number fall in the correct range for the 3C carbs?

carbspecs.jpg
 

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Discussion Starter · #6 ·
Yup, my engine serial number falls in the range for the 3-C carbs. Here are the photos per request.

IMG_3169.JPG IMG_3170.JPG
 

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Yep, those look like the wrong floats. You can even see it in the picture. They just don't look right.

I have been into 350A carbs recently and all the later ones but couldn't remember if the 3C used the round or square floats.
 

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Discussion Starter · #9 ·
Ugh….

Why do people (i.e., POs) do this?! I'm finding a bunch of things like this all over the place! I read the manual once to check the machine, and I'm finding small mistakes everywhere that causes huge problems down the line. I was adjusting the valves yesterday and the indicator marks where not where they're supposed to be. Sorry, venting a bit.

Thanks hahnda and outobie, I'll reintroduce the correct floats to my carbs.
 

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One good thing about PO's mistakes is that its a learning opportunity for us. I've learned so much over the years fixing bikes where the PO did some strange thing that I would have never had the chance to learn.
 
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