I have a leaking fuel cap(new seal kit installed), and a pressurising tank .... vacuum after riding and pressure when sitting in the sun.
I have been blowing compressed air in the vent tube under the tank and it appears the burrito is blocked...(the water drain was also blocked, but was easy to clear)... 
I have poked wire up the vent tube and I can get it all the way up to the burrito , where it stops.... this is not easy to do, and I can only get so much pressure on it.... the small hole in the burrito is clear, I can poke it with wire..

It kind of looks like I will end drilling a hole in the burrito to give me access to the top of the tube where it enters the burrito.... the tank has quite a layer of varnish, so will need a clean out anyway....

thoughts?... I did lots of googleing and this doesn't appear to be a common issue...

this is the best pic I could find of the burrito 

Was the tank removed and inverted when you attempted to clear that line? Are you using air pressure directly into a port that connects to the burrito, or is there a hose connected to the port?

I wouldn't start grinding until there is more proof of blockage and other methods of clearing blockage are tried.

Laitch wrote:I wouldn't start grinding until there is more proof of blockage and other methods of clearing blockage are tried.

 have you tried throttle body cleaner or acetone  injected into the outlet pipe  whilst inverted , leave inverted to let it soak through ? 
you may have to fit a section of pipe to the other end of the breather (the bit that leads to the pump body  and the small section tube that attaches to the filter basket at the bottom of the pump)  and inject cleaner there also


might be an idea to make a plug in the fuel tank lid area out of rubber and screwed in place with a backing of plywood to hold it with the 4 x 4mm screws that hold the filler cap

then can fill with fluid and soak

white vinegar seems to remove a lot of the crap varnish and is cheep as chips  although scrubbing is required to remove off the surface properly   stinks like the proverbial though ….grin

just an idea worth exploring

charlie99 wrote:. . . white vinegar seems to remove a lot of the crap varnish and is cheep as chips . . .

You can sprinkle it on your chips, too.

Laitch wrote:Was the tank removed and inverted when you attempted to clear that line? Are you using air pressure directly into a port that connects to the burrito, or is there a hose connected to the port?

Thanks Laitch.... 

I haven't removed the tank yet... 
I had a hose zip tied to the outlet... I had 120 psi going in.

charlie99 wrote:

Laitch wrote:I wouldn't start grinding until there is more proof of blockage and other methods of clearing blockage are tried.

 have you tried throttle body cleaner or acetone  injected into the outlet pipe  whilst inverted , leave inverted to let it soak through ? 
you may have to fit a section of pipe to the other end of the breather (the bit that leads to the pump body  and the small section tube that attaches to the filter basket at the bottom of the pump)  and inject cleaner there also


might be an idea to make a plug in the fuel tank lid area out of rubber and screwed in place with a backing of plywood to hold it with the 4 x 4mm screws that hold the filler cap

then can fill with fluid and soak

white vinegar seems to remove a lot of the crap varnish and is cheep as chips  although scrubbing is required to remove off the surface properly   stinks like the proverbial though ….grin

just an idea worth exploring

thanks Charlie...

I will remove the tank next weekend and use some acetone on it.

I dont think the tubing from the pump(green circle) enters the burrito .... it ends alongside it.
Same with the mystery spigot(yellow circle) doesn't enter the burrito ..
The only entry seems to be the very small hole (blue circle) and the vent tube(red circle), where the blockage appears to be.

does this help

In my '86 model K100, the yellow stub comes in from the fuel pump screen, the blue hole is...just a hole, the red goes to the tank overfill drain and the green is the return from the fuel pressure regulator.

I know that you know what some (or all) of these connections are for, but I am clarifying them to those whom may not be aware.

I hope this helps.

  spot on Blakey