Carb questions, 1986 VF500

I am trying to bring a rescued 1986 VF500 back to life, starting with carb cleaning. Symptoms were typical: barely starts, barely runs, dies with any application of throttle. Excellent fuel flow into all 4 carbs has been verified.

I have a few questions/suggestions:

1) For a bench synchronization the factory service manual says "...align...the throttle valve (the butterfly) with the edge of the bypass hole". So, which edge? Should one see the entire hole or should it be just hidden? My copy of the FSM is poor so that detail of the photo is illegible.

2) I seem to have a vent/vacuum tap that I haven't seen in photographs of other carb sets. Its the one with a red cap in the middle of the first photo, on carb #2. It goes straight through into the carb throat, lives at the bottom of the main casting, just above the bottom cover. I put the red cap on for the photo, did't have one on it when I got it. California plumbing maybe?

3) At some point of this process a small brass washer appeared on my workbench under the carb assembly, second photo shows its size relative to the drilled out pilot screw plug. I didn't see this style washer anywhere else during the cleaning.

4) Third photo is of a short wood dowel I used to hold the butterfly full open during the process, made things much easier.

5) If I blew compressed air into the channel at the top of the entrance to the venturi (fourth photo) it would act on the diaphram and gently lift the slide. I was able to verify the proper movement of the slide in a near-real test.

6) The only real blockage was in the idle jets, two of which were completely blocked. As it turned out a .012 drill bit was the perfect size to clean it out. Tiny!

Tom

 

There is a tube on each carb that if you have a California model bike they should all be capped... I removed the emissions crap on my 86 vfr700 and have caps on these. sorry I can't get pictures ( bike is under a tarp which is also covered with snow....) to show you. check you float valves and make sure your mail jets are clean... good luck!!

and welcome to the World....

 

Yes, I should have pointed out I have the 4 angled tubes and they have blue caps on them. The one I am asking about is a 5th.

Tom

PS: Tell me about "This thread is worthless without pics"? You can't see them? Are you logged in?

 

That washer looks like the one that goes on the end of the pilot screw between the spring and the oring.

 

Make a compression test on the engine to see what you're working with. Report back with any running problems. Carbs look clean, but it's good to drain and flush the fuel tank, checking for crap or rust, b4 connecting it to newly-cleaned carbs.