Topic: '78 550 Float Height Redux

[Brian G]

Hi Everyone -

For some reason (distortions of time and space?) I simply can't get my head around the written descriptions of '78 CB550K float height settings which I've been able to find via the 'Search' function. Would some kind soul please try again in words containing as few syllables as possible?

Referring to the below photograph - the float tang (just visible behind the vernier pointers) is barely touching the float valve spindle which hasn't yet begun to close.

The verniers are set to 12.5mm which I believe is correct for the '78 carbs - or it may be 14mm depending on which posting I read 



Obviously, the float needs adjustment as the 12.5mm spacing doesn't align with any part of the float body. My question is: where should I be measuring 12.5mm? At A-A, or at B-B? Or somewhere else?

Thank you kindly for your enlightenment!
Brian

[Sporkfly]

14.5 mm at point B is how I've always done it... No overflow or fuel starvation issues here.

[TwoTired]

I know the specs are 12.5 mm for the 78 CB550K.  I have one.  I don't think the carbs had been touched since it left the factory until I opened them up.  The floats were set to 14mm and I left then at that setting.  I have no complaints on how it runs.
14mm will pretty much have the float bottom parallel with the bowl mount flange.  But, per your drawing, B is the measurement point.  A 12.5 mm setting will make the engine run a bit richer.  Which is probably beneficial if you plan on using the Foam Uni, instead of the stock paper filter.