Topic: VB44A Carb Questions

[Wayfarer]

I have some questions about these VB44A carbs off an '81 CB650C, which are not covered in my Clymer manual.

1.  Besides the two metal fuel tubes, there is a rubbery tube joining carbs 2/3.  There are corresponding T-connectors between 1/2 and 3/4, which each have a hose routed upwards & inwards to join in a 3rd T above the center of the carbs.  From there, another hose goes rearward.  (If you have a Clymer 650 manual, see figs. 53 and 55 on p.192-3; you can see the hoses.)  What is the purpose of this plumbing?

Inside the carb bowls are two passages, about 5mm wide, that lead up to these hoses.  Could it be an overflow?  But why route it way up above the carbs?

2.  In the pre-81 carb bowl cleaning text, Clymer says something like, 'make sure the overflow tube is clean'.  There is no such reference to the '81 carbs.  Is there no overflow?

3.  What is the purpose for the accelerator pump on carb #2, and how does it work?


TIA,
Tim

[cb650]

It is a vent/overflow.  But to overflow it would be on its side or a very flooded cyl.
The acc pump is to overcome the lean factory settings of the carbs for emisions.




                                        Terry

[Wayfarer]

Thanks.  A vent makes sense, but it's a poor design for an overflow.  By the time the fuel got up to the 3rd T, the jugs could be full of fuel.  Oh, well...