Topic: 75 cb550f carb questions

[Massless]

Hello everyone! This is my first post. I have a 1975 cb550f that came with 087a carbs on it. The proprietary carbs are 069a from all my research. So I ordered a nice set of 069a. The floats in my new 069a seems to be in worse shape than the floats in the 087a carbs so I want to switch them out. They seem very very similar but there are very slight differences I can tell. Is it ok to switch parts from these 2 carbs around? The main jets look the same but the slow jets are also different. Other than that all components look the same. Thanks for any help!

[Scott S]

 All CB500/550 carb bodies from '71-76 are the same. The differences were in the jets, possibly needles, air screws, etc.
 You should be fine swapping the parts around. Be sure to check/set the float height and bench sync the carbs while they're off the bike.

[Massless]

Excellent thank you for that great information. Do you happen to have a good resource or tutorial link on setting the float height? Is 22mm from gasket surface of the carb body to the bottom of the float when it's fully depressed against the needle?

[Massless]

If I blow through the fuel line and raise the floats slowly there's a point where it starts to travel through the needle I assume this is the same point that fuel is allowed in. Do I set my float height to the point that it cuts off fuel?

[flybox1]

The easiest way to ensure proper fuel level is to perform the clear tube test, and set your float height per your results

http://forums.sohc4.net/index.php?topic=149299.0

[Scott S]

Excellent thank you for that great information. Do you happen to have a good resource or tutorial link on setting the float height? Is 22mm from gasket surface of the carb body to the bottom of the float when it's fully depressed against the needle?

 Not fully depressed. You want the float just resting on the needle, right before it starts to depress it. I use a block of wood and angle the carbs slightly.