Weird no fuel condition

My 85 XJ700N has less than 11,000 miles on it, and is in pretty good condition, with all original parts. before the issue, it ran very well, although pretty rich. I have owned it 2 years and bought it from the original owner.

I pulled my carbs a while back when the bike started running poorly, idle creeping up and smelling gas in the oil. I checked them all for stuck floats and valves, checked static float height, gave them a basic once over and put them back together. I thought I was having a fuel overflow issue, so I did not give them the full treatment. I didn't see any obvious problems like a stuck valve.

Got it all back together and now I have a weird problem. Put gas in the tank, set the petcock to prime, and no fuel flowed to the carbs. I fussed with this for awhile, tried cranking it at every petcock setting to get fuel to flow - no luck. I pulled the fuel line off the tank and checked that the petcock flows at the prime setting - no problem.

I put it all back together, set to prime for 15 minutes and then opened the screw at the bottom of bowl #1, but there was no fuel present there or at #4, which I also checked.

Any ideas what might be the issue? Do I have an airlock problem? Any suggestions for diagnosing the problem, or solving it? Thanks in advance.

 

first thing is how much fuel is in the tank?

fuel filter?
kinked fuel line

wrong hose hooked to petcock?

 

No fuel filter. Vacuum line from #3 carb boot to petcock vacuum port. Fuel line properly installed to petcock. Same line that was working before. About a third of a tank. Without fuel line attached to petcock, fuel flows from the petcock on the prime setting, which has been the setting I have been using trying to get fuel to the carb bowls.

No gas leaking anywhere.

 

How rusty is the tank?
My WAG is that crap from the tank is blocking the T fitting on the rack.

 

The tank is not bad. When I first took it off, I washed it out with fresh gas, and poured it out the filler hole, and there was a few small particles in the gas. No rust, but some varnish. You might have something there. If the carbs have to come back out, I will look here first. When I took them apart, there were a few grains of crap at two of the float screens.

 

Removed the carb rack AGAIN today. Pulled the fuel line off the T and checked it, and it looks like there is a piece of hard rubber from the inside of the hose that has come away and partially blocked the T at the connection to the fuel line, near as I can tell. I'm thinking the fuel line may be original to the bike, so I am going to check for other debris and buy a new line and see if I can get it all back together and started tomorrow. Thanks for pointing me in that direction, K-moe.

 

6mm fuel line

while you have the carbs off flush the fuel rail. from the needle body back up the line. get all the bits out

 

if the fuel line crumbled, what do the brake lines look like

 

Will do. Got the section of fuel line today.

Good question. Most of the original rubber parts on the bike look pretty good for close to 40 years, but redoing the brakes is on the list for sure.

Thanks for the help.

 

Got her back together and she runs, after the coldest of cold starts.

 

Looks don't mean anything. You can't see what's happening on the inside.
Why You NEED TO REPLACE Original brake lines w/pics