Floats on a ‘79

[loxley007]

Hi all, I’ve just rebuilt my carbs and I noticed that my 79 has brown plastic floats (and not adjustable) in the carbs. The manual and CSMNL etc suggest they should have black floats that are adjustable.

My problem is that carb 1 and 2 are leaking fuel so I’m looking to adjust the floats which I obviously can’t do given they are plastic.

So, my question is, which floats should I have - brown plastic or black with metal tab?

 

[loxley007]

Some info from elsewhere. Cody at MotorcycleMD suggests the black/metal tabs are OEM for a 79 so it looks like someone has replaced them at some point with plastic brown/non adjustable ones. I’ve bought 4 new ones from CSMNL.

 

[Loose Chain]

You will need the correct needles to go with the floats you plan to use. You may not have a float problem and it could be the needles on those 2 carbs not seating properly. The brown ones you are talking about didn't start off brown, they just went that color over time. The none adjustable floats take the guess work out of that part of a rebuild for people that don't know what they are doing. How did your float measurement go when you did the rebuild? Your bike probably had the none adjustable floats from new.

 

[lajos]

You will need the correct needles to go with the floats you plan to use. You may not have a float problem and it could be the needles on those 2 carbs not seating properly. The brown ones you are talking about didn't start off brown, they just went that color over time. The none adjustable floats take the guess work out of that part of a rebuild for people that don't know what they are doing. How did your float measurement go when you did the rebuild? Your bike probably had the none adjustable floats from new.

I second on that. In my case, carb 3 was leaking and the problem was the float valve seating, and not the float. So it is worth checking before go to a shopping spree

 

[loxley007]

Cheers all. I will look into that asap.

 

[Bo82CB]

When you overhaul your carbs use small Q-tip with some fine polish and polish float shut-off valve seat!

 

[gaszek]

Hi! I'll jump into the thread—maybe someone can help me out. I have a 1981 Honda CB 750 that originally had plastic floats without height adjustment. While cleaning the carburetors, I replaced them with new adjustable floats (like the ones in the photo). The old needle valve doesn't fit the new float, and the spare valves I had in my garage (probably from a different Honda) are unfortunately leaking fuel. Does anyone know the exact dimensions or, even better, have a link to a store where I can get the correct needle valves?

Or maybe I'm thinking about this the wrong way and I did something incorrectly? I've disassembled a few carburetors before, but I've never run into this kind of issue.

 

[Bo82CB]

Well bring out your measuring caliper and measure both needles. This way you will see the difference if there is one...

 

[loxley007]

Weird…the needle valves I used had a ‘hook’ that attached them to the floats. Your old ones look like they just slide in. The attached image shows the hook.

Mine was for a 79 CB750.

Not sure this helps you much…