Topic: Float adjustment...

[russouno]

Can anyone tell me where to measure the float for adjustment on my 78` 750sohc?
The manual shows the floats that are 'round', the floats I have are long and rectangular... I know the spec is 14.5 mm but where on this do I measure?? at the tip of the float, in the middle of the float, or at the back end (near the needle) ??

thanks!

Joe

[Bob Wessner]

This might help. Be sure to note why he is measuring the way he is rather than the way he should.

http://www.salocal.com/sohc/tech/carb/asmpg_mgs/flthgt.htm

[russouno]

I have already checked out that page... it has the round floats.... those are measured at the tallest point of the float... mine are rectangular shaped...

[russouno]

Nobody knows?    for sure somebody has the 77/78 carbs and has rebuilt them??
: (
wow....

[mark]

The 'Honda Common Service Manual'('80s), the earlier 'Honda Motorcycle Carburetion'('60s) manual, the page linked above, and an old Clymer 550('70s) book all show the gauge held in line with the main jet - basically the middle of the float. Carb in left hand, gauge in right, float pin up, don't compress the needle spring. Hopefully the plastic floats haven't sponged up fuel.

Happy trails.

[Bob Wessner]

I have already checked out that page... it has the round floats.... those are measured at the tallest point of the float... mine are rectangular shaped...

You measure from the same point on the float regardless of the shape.

[jdpas29]

i have the same model bike as you and i have done the float height.  stay calm.   

use the MIDDLE of the float.  it helped me to measure and make a mark on the middle of the outside of the carb body so that my spot for the gauge was the same across the board on the carbs.  this spot should also line up somewhat with the middle of the float itself. 

http://www.salocal.com/sohc/tech/carb/asmpg_mgs/flthgt.htm

you should measure from the actual gasket surface for the appropriate float height which is hard to do but an easy way is to just add a couple of millimeters to your measurement for that difference.

make sure that the float is just touching the pin and not compressing it which... it depends on whether you're doing this job with the carbs on or off of the body.  are the carbs on a workbench or are they on the bike?
 

[BobbyR]

I actually went to the bottom of the float to the float bowl lip. My thinking was the float sits on top of the gas. Works fine. As other have said in other posts. I used a simple ruler with a red line I marked at 14mm so my old eyes had a quick reference. Runs fine from 0 to 100 Mph.   

[russouno]

Just a heads up.... I downloaded the 'Honda Shop manual that was listed in the forum under a different post.  Printed that baby out, laminated it and then bound it to an official manual. The manual was for the 1978 CB750K / F models only.  It showed the exact float I had and listed with a picture that measuring the float at 14.5 mm at the very TIP of the float. (farthest from the needle valve) Basicly, this makes the float lay level when the needle valve is to be closed.  This is shown on page 4-10 in the manual with a very nice pic/diagram.  This 'official manual is the best thing EVER!!!!!

Thanks again everyone!!!!!!!