Gen 3 bulkhead fitting

[Wistrick]

so my vent line is clear....1/4 inch

plumbed into front nipple 1/4...(shortened up fuel line ,had  excess so I could lift tank with out disconnecting,  ) 

verified that no crazy bends and line not pinched....

blew air in aux tank vent line and fuel came out of the cap at the hole wit the red rubber gasket....

would take pliers to pinch off fuel line so I don't thin its collapsing....

So best I can tell is I am getting transfer because, if I do freeway speeds for a couple miles and come back and open the main fuel cap, I can see fuel coming out the vent hole....

will try again today, maybe the shorten fuel line will help

 

[Wistrick]

This works because using fuel from the tank creates a slight vacuum which draws more from the auxiliary. (Not gravity fed). If the seal at your tank lid is imperfect, it may draw air through there rather than gas from the other tank.

You said you only rode 45 miles - should have been more than enough to start drawing unless you were opening the tank frequently to check.

I took the little ball out of the fuel cap now I wonder????

 

[RossKean]

I took the little ball out of the fuel cap now I wonder????

That would do it, I think.

 

[Wistrick]

That would do it, I think.

Its my understanding that the ball its just a tip over valve and shouldn't affect it....when I had the tank plumbed in via gravity on the 07 I had to remove  it to prevent vapor lock in hot weather...Same thing on the Tenere

 

[RossKean]

If removal is preventing vapor lock, it means it is allowing air to be drawn into the tank.  The problem with the ball is that it gets gunked up and sticks.

 

[Wistrick]

ok riddle me this I went out and turned on the ignition this morning and the main tank showed full when it was down 2 bars last night... almost like its gravity feeding  not understand.....

 

[Wistrick]

If removal is preventing vapor lock, it means it is allowing air to be drawn into the tank.  The problem with the ball is that it gets gunked up and sticks.

I reinstalled it

 

[Canadian FJR]

“ok riddle me this I went out and turned on the ignition this morning and the main tank showed full when it was down 2 bars last night... almost like its gravity feeding  not understand.....”

Mine did the same thing when I first tested it.  At least you confirmed that it will transfer.

Canadian FJR

 

[Wistrick]

I confirmed with @travel_man that his will do the same sitting over night...Going for a 100 mile test run here in a bit...

 

[RossKean]

“ok riddle me this I went out and turned on the ignition this morning and the main tank showed full when it was down 2 bars last night... almost like its gravity feeding  not understand.....”

Mine did the same thing when I first tested it.  At least you confirmed that it will transfer.

Canadian FJR

I think that is why you noticed a bit of gas around the cap.  Also why I thought some sort of three-way valve to shut it off might be a good idea.  Some air is escaping the tank and it is gravity feeding to some extent.

See my post at the end of this thread..

 

[Wistrick]

Well for whatever reason it seem to be working now... Took a 100 mile ride and fuel gauge.  never moved off full... On way home I topped off the aux tank and it was down around 2 gallons so...Only things I did was put the ball back in the fuel cap  and shorten the fuel line from the aux to the main tank by 6 inches...Seems to be working as advertised....

thanks for all the input guys

Dan

 

[Canadian FJR]

Good to hear, thanks for the update.

Canadian FJR

 

[Canadian FJR]

I had a small amount of weeping around the main fuel tank cap.  I removed it and cleaned things up, seems to be a bit of Alaska dirt in there.  Reinstalled and no more weeping.  This setup is working perfectly.

Canadian FJR

 

[Brodie]

“ok riddle me this I went out and turned on the ignition this morning and the main tank showed full when it was down 2 bars last night... almost like its gravity feeding  not understand.....”

————————————————————————————
My gut thoughts are that the fuel transfer line that you are using between the tanks is not rigid enough, and is collapsing somewhere along its length. This will cause a high vacuum within the main tank with virtually no fuel transfer between the tanks. You parked your bike the night before with high vacuum inside, two bars showing, and plenty of fuel in the aux tank. It took some time (overnight perhaps) for enough fuel to suck through this restrictive line until the vacuum dropped low enough for the fuel transfer line to open back up and flow sufficient amount of fuel to replenish the main tank and bring it back to atmospheric pressure. 
 

Look into replacing your fuel transfer line with stiff non collapsible fuel line designed for fuel delivery from a tank to a fuel pump. Have a good look at Travel Man’s picture of his blue fuel line attached to his main tank. 
 

Be careful with the line you are currently using. When collapsed, your main tank will be subjected to increasingly greater internal vacuum – until implosion and permanent deformation. 
 

Brodie

 

[Wistrick]

“ok riddle me this I went out and turned on the ignition this morning and the main tank showed full when it was down 2 bars last night... almost like its gravity feeding  not understand.....”

————————————————————————————
My gut thoughts are that the fuel transfer line that you are using between the tanks is not rigid enough, and is collapsing somewhere along its length. This will cause a high vacuum within the main tank with virtually no fuel transfer between the tanks. You parked your bike the night before with high vacuum inside, two bars showing, and plenty of fuel in the aux tank. It took some time (overnight perhaps) for enough fuel to suck through this restrictive line until the vacuum dropped low enough for the fuel transfer line to open back up and flow sufficient amount of fuel to replenish the main tank and bring it back to atmospheric pressure. 
 

Look into replacing your fuel transfer line with stiff non collapsible fuel line designed for fuel delivery from a tank to a fuel pump. Have a good look at Travel Man’s picture of his blue fuel line attached to his main tank. 
 

Be careful with the line you are currently using. When collapsed, your main tank will be subjected to increasingly greater internal vacuum – until implosion and permanent deformation. 
 

Brodie

this wasn't the issue,  the fuel line is so rigid that you couldn't pinch it of with your fingers...After reversing the ballectomy on the gas cap (reinstalled the ball) the system work flawless....

 

[Canadian FJR]

Another experiment last evening.  I was told not to just fill the auxiliary tank without filling the main tank also, it could create an air lock.

Down to one bar so I knew the cell was completely empty, also no fuel in my see thru filter.  I filled just the cell, absolutely no issues. Ran at one bar for 100 kms before raising to two bars.  
 

Canadian FJR

 

[Wistrick]

Another experiment last evening.  I was told not to just fill the auxiliary tank without filling the main tank also, it could create an air lock.

Down to one bar so I knew the cell was completely empty, also no fuel in my see thru filter.  I filled just the cell, absolutely no issues. Ran at one bar for 100 kms before raising to two bars.  
 

Cabadian FJR

wonder if it would be more likely to air/vapor lock in hot weather...... ???  

 

[Canadian FJR]

Hot weather - May in Nova Scotia, that’s funny.

Absolutely no issue, it worked perfectly.  Sorry for the poor description.  I was just trying to explain that the plumbing is working well.

Canadian FJR