Gas Tank Vacuum Sealed?

[R3Rx118]

Well I installed a new slip on and it appeared to be running good at first. Then I noticed a lot of decel popping and it seemed to be a little sluggish. Didn't notice it at first and thought it was my imagination that it was getting worse. Well I go to fill up this morning and could barely pry up the gas cap. Actually saw the sides of the tank move when the vacuum was released. On the up side, when I continued my ride to work the decel popping was gone and it seems back to it's good old spirited self so I guess it actually was getting worse and running lean if it couldn't suck in any fuel.
So now the big question....WTH is causing the tank to get vacuum locked like that? I've read the vent line, or something inside the tank, charcoal filter.....any ideas?
(LOVE this forum but sometimes I get on information overload.)
FWIW....I have had the tank up a few times recently...head replaced and new throttle cables.

 

[rocketjohn]

This is a thread I will watch.....I never heard of such a thing!

 

[Claviger]

There are two vent line that run from the fuel neck to the front left of the tank. It is a pain to replace or clear them out, but, in your case you can at least troubleshoot where the blockage is fairly easily. If you pull the tank up, you will see the two nipples with hoses on the tank. Try disconnecting them both and see if it still seals air tight. If it doesn't any more you have a blockage outside the tank, if it still seals, you have a blockage inside the tank.

Once you isolate it, if it's outside, just replace the hoses. If it's inside, take to mama T since you're still under warranty and make them do it

 

[Triple Trouble]

Chances are you pinched the vent line. Lift the tank and replace carefully.

 

[TURBO200R4]

i would look for kinked lines coming from tank. or some bracket closing off the vented hose going to canister.
those later bikes may have a solenoid that has been disconnected.
u might want to use something to keep the cap from sealing so it does not flatten your tank.
idk or ikd has the manuals in his posts u might take a look
i am sure some one can tell u more.

 

[TURBO200R4]

reading the other post reminded me of a job i had (on a car) where someone had switched the lines when they had the tank off.

 

[R3Rx118]

Yeah I see in the manual it specifically mentions to mark which line came from where....so I'm wondering if 'someone'...not me...didn't pay attention when doing that work.

 

[R3Rx118]

Does anyone know if the X's are CA models with the evap system or are the the non CA version?

 

[sonny]

I do not have the C.A. version on mine. Did buy a bike in V.A. once (Shadow 1100 Honda) that was C.A. equip.

 

[R3Rx118]

I do not have the C.A. version on mine.

Good to hear...hope mine is the same. That'll eliminate one possibility.....I hope!!