1983 Carburetor Plumbing Question

Started by kevin g, May 31, 2019, 08:25:11 PM

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kevin g

I am working to get my recently acquired Vision back on the road.  It was not all assembled when I got it so I need some help.  I have poured through all the drawings and parts fiches but cannot figure out two things:

The accelerator pump has a vacuum operated appendage associated with it and I cannot figure out where the vacuum line coming out of the bottom of this thing goes.    Can anyone help me?

There are two black overflow hoses about 1/2" diameter that run up the left side to the area of the carburetors, I cannot figure out what those lines attach to.  Can anyone tell me?

allstateguy

There are two black overflow hoses about 1/2" diameter that run up the left side to the area of the carburetors, I cannot figure out what those lines attach to.  Can anyone tell me?

to the bottom of the airbox

The Prophet of Doom

The vacuum goes to the joints that connect the carbs to the engine.  Front if I recall correctly.


Because there are two of them, the hoses are probably the carburetor air vent hoses.  They go from the back of the choke plungers   They are not normally black, but may have been replaced.  There is only one carb overflow that goes to the front carb, then a short hose that links back to the rear.
In both cases they route to the hole in the frame in behind the battery.


All the cable and hose routing is detailed  with pictures in the 16R Service Manual and the 11U Service manual - both available from the Resources page

jefferson

Those vent lines attach to the spigots on the top of the carbs. One should be longer as it goes to the front carb.

kevin g

Last night I figured out the two vent tubes at the choke plunger.  I think I understand that the accelerator pump vacuum line attaches to the rear cylinder vacuum port on the intake.  Please verify that I have these connections correct:

  Accelerator pump vacuum to rear cylinder intake port
  Fuel pump vacuum to front cylinder large vacuum port
  Petcock vacuum to the front cylinder small vacuum port

One other thing, I think I might be able rebuild the fuel petcock.  I think the vacuum membrane is the same as other petcocks so it can be replaced.  I have been looking at the fuel return contraption and I think I can rebuild it by taking the plunger valves from new kits and making a new membrane.  I have found a source for the membrane material so I might give it a try.

You can still get new petcocks for a 1983 so I will probably do that as well.

Walt_M.

I'm not looking at the manual and no longer have the stock carbs on my 83 but I don't think the accelerator pump goes to vacuum. There is a little filter that goes to the accelerator pump,  I think. The 3rd vacuum connection goes to the air box flapper.
Whale oil beef hooked!