have you tried all this with the fuel cap open? If the vacuum relief line is plugged for the tank it will build up vacuum and not allow fuel to flow. Also, to make sure its not your fuel switch valve, remove the tank and attach some sort of fuel supply to the fuel line, right before the fuel filter.

 

The F3 petcock does not have a vacuum line, that's only on the F2s. It goes directly into the fuel pump and from there to the carbs. Personally I have my fuel pump bypassed with a gravity feed system because I got tired of screwing with them. The real pain in the *** with the fuel pumps is that their contacts wear so the problem is typically intermittent. To troubleshoot and make sure that your carbs are getting enough fuel I would set up a temporary gravity feed system. If the problem still exists then you know that the problem does not lie in the fuel pump and at that point you would be able to start tearing into your carbs, looking at your air/fuel mixture screw and jets. If it did fix your problem, then your problem lies in the fuel pump.

 

+1 on Cinderfella. I too have had problems with my fuel cut relay recently and I have since then just bypassed my fuel pump and did a gravity feed and the bike runs like a champ! Obviously I would like to fix the problem at hand but this is an idea that could potentially rule out a lot of guess work.

 

Just for a quick side question. - When the bike is idling I notice that I can really hear the cam chain tensioner. Im sure it could use a replacement. Anyhow, is it possible for the bike to jump mechanical timing from this?

 

Yes it is possible, not likely but it can happen. Depends on how bad the cct is and how hard you run the bike.

 

Possible but not probable, I think you would be having a world more problems if your bike jumped timing. As far as I know, the engine is not non-interference, meaning that your valves and everything would be screwed. The bikes are notorious for bad CCTs but that's what manual cam chain tensioners are for.
As far as the problem at hand though, I'd say (and hope for your sake) unrelated.

 

I hate to keep repeating myself, but what you're describing is classic symptoms of clogged idle circuits. When you engage the choke, it opens a circuit in the top of the carburetor (not shown in the photo below) to enrichen the air-fuel mixture. That's why it runs with the choke on. I believe that your idle circuits are clogged. There are 2 places that have to be verified to be clean. First is the larger opening and second is the 2 smaller openings next to the throttle plate. The larger opening is where fuel enters based on the Air-Fuel mixture screw adjustment.

If you have not removed this adjustment screw and verified that the passage ways are clean, then you need to. The 2 smaller openings are exposed as soon as you start to open the throttle. They have to be clear as well. You should be able to get carburetor cleaner to go through the idle jet (the jet you can't remove when you take the bowl off) and out these openings.

When the throttle is fully closed, air is actually going into these 2 small openings and coming out the larger opening along with fuel. This is all part of the idle circuit.

In this photo, the throttle plate is opened just slightly, exposing the low speed orifices.

 

The bike is back in commission and on the road again. Additional carb work took care of the issue. Thank you all for your help