Vacuum sound when opening gas cap

[thought]

Hey guys, this is sort of something related to this thread:

http://www.ducatimonsterforum.org/index.php?topic=48215.0

So I checked the hoses on the tank on my m796, and they seemed ok, but I still get a vacuum/air rushing in sound when opening my gas cap when i fill up my tank.  Is this normal or should I check for kinks again?  I haven't noticed anything as bad as the orig post e.g.no expansion, just a slight vacuum.

Does everyone else get that sound too?

[EEL]

your vent line from your tank is clogged..

it should not make a suction noise. You'll fry your pump or get a reduced pressure at your injector assembly. Check your hoses from your tank and make sure the vent and overflow lines arent pinched. Better yet, make the dealer earn his commission.

[thought]

your vent line from your tank is clogged..

it should not make a suction noise. You'll fry your pump or get a reduced pressure at your injector assembly. Check your hoses from your tank and make sure the vent and overflow lines arent pinched. Better yet, make the dealer earn his commission.

dammit.

i was hoping that it was normal... i'll go check the vent lines one more time and if it's still happening, i'll bring it back to the dealer.  it should be covered under warranty work right?

[EEL]

Should be. Unless your dealer is a "point the finger back at your kind"

[DDDuc]

I had the same problem on the M1100.  Took it to the dealer and they said that they have seen this a few times.  apparently the hose that goes from the tank to the emissions canister has a sharp bend in it.  when it gets hot from its proximity to the engine, it can collapse, cutting off flow.  The dealer said they can fix it (under warranty) or remove the emissions canister.  My bike is now lighter . . . the problem is gone.

[2-Skinny]

Step 1: Clear hose of clog.

Step 2: Remove emissions canister/ use silicone or vinyl caps on throttle body nipples.

Bike looks better/ tank problem likely to not happen again.

[thought]

thanks for the info guys, i popped the tank covers off and messed around with the hoses... vacuum kept on happening even after the hoses were totally free of any kinks.  so it's at the dealership now because i didnt want to bother looking for the clog... and ddduc, i guess i'm not the only one.  haha

i'm prob going to hold off taking off the canister till the winter though...  haha, dont want to waste the nice weather.

[2-Skinny]

If it matters, it takes like a half hour to remove it- and that's if you don't know what you're doing...

[Raux]

you can do a check by just totally unhooked the hoses and see if you still get the issue. might be the valve itself

[thought]

i figure by this point, as it's still under warranty, let the dealer take care of it...  they picked up and will deliver for me so it's not that big of an issue to get it to them.

and i'll go ahead and order that euro side cover for the canister...  maybe i'll do it this summer then if it doesnt take too long. 

[thought]

just a quick update... they looked at it, and they said that a lot of other bikes also had this issue, but my vent hoses arent clogged either.  basically they said that they guess it's normal, and i didnt want to bother telling them about the kink from the engine heat.

placed a order for the euro side cover, i'll be deleting the canister once it comes in

[OT]

Actually, it's the sound of the gasoline companies sucking the money out of your wallet.... 

[bdub]

when I had that problem my tank vent was clogged. Compressed air into the vent fixed it.

[BoDiddley]

when I had that problem my tank vent was clogged. Compressed air into the vent fixed it.

Just curious for future refernce, what would clog a vent hose?  And anyone doing the Caswell trip be sure to cover the vent fittings.

[Ddan]

The hose in the tank can deteriorate enough that it collapses shut.  You can still blow air through it but it won't vent properly.