Author Topic: Gas pressure building up  (Read 3718 times)

Jackolicious

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Gas pressure building up
« on: January 13, 2015, 04:58:50 PM »
Hi there! I’ve been browsing your forums for a while and you seem like a great group. Excited for my first post!

I bought my 2010 V7 in late summer 2014. After my first long ride, I parked it in my garage that has very little ventilation, and went to bed. The next day, I found it had a puddle of gas under the bike. I found drips coming out of a drain hose under the bike and it seemed to have leaked out of the filler cap as well. I made sure the fuel lines were clear and replaced one.

Next long ride, I came back and found another gas puddle. I popped the gas cap and felt a puff of pressurized air.

Next stop was at the shop. They found a crack in the tank (no idea why MG decided on plastic). I went into 12 weeks of waiting for a new tank from MG. Thankfully they warranted the repair. The reason I was given is that the high ethanol content of gas in California would cause expansion in the tank. That caused the crack.

Just got the bike back and took it on a long ride. Parked it, left it for an hour or so, then popped the gas cap. Again, the large puff of gassy air.

I haven't seen gas on my floor yet, but I don’t want to crack another tank. I don’t want more puddles of gas on my floor. Is what I’m experiencing normal? Should I fix something? HELP! ???

Offline rodekyll

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Re: Gas pressure building up
« Reply #1 on: January 13, 2015, 05:04:40 PM »
Yes, you should fix something. 

I was going to stop there, but I've been told that snark isn't the new funny.   :BEER:


You have a fairly routine tank vent issue.  Either the tipover valve is not oriented correctly, there's a kink in the vent hose, or the vent valve is wrongside up.  I'm surprised that the shop didn't chase that when you reported the symptoms.  You did report the symptoms, didn't you?

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Offline pocphil

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Re: Gas pressure building up
« Reply #2 on: January 13, 2015, 05:17:27 PM »
I'd start with a canisterectomy...lo ok it up on this forum, easy and will probably solve your problem immediately. If it doesn't check under the tank for a pinched hose.

Phil Waters
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Offline Wayne Orwig

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Re: Gas pressure building up
« Reply #3 on: January 13, 2015, 06:20:57 PM »
I thought this was a thread about my wife's chili soup......


 :wife:

If it is a small puff, that is normal. There are valves in the vent line to reduce the amount of fumes that belch in and out of the tank. If you rip out all of the vent restrictors, then you will open the tank to moisture and such. And your fuel will go stall much quicker. If it is a LOT, then you want to correct it. From what you describe, I believe you are talking about a normal, small amount of pressure.
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Re: Gas pressure building up
« Reply #3 on: January 13, 2015, 06:20:57 PM »

dilligaf

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Re: Gas pressure building up
« Reply #4 on: January 13, 2015, 07:37:27 PM »
You beat me to it Wayne.  ;-T  :BEER:
Matt

Offline guzzisteve

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Re: Gas pressure building up
« Reply #5 on: January 13, 2015, 08:19:34 PM »
There was a Tech Update on 09-11 models for a free flowing canister valve PN 860138 it is blue & orange. Old valve is grey.   It is behind the LH throttle body toward inside.  The shop should have replaced it also. It will have no pressure in tank w/new valve. AND it's free from Guzzi.
Tech Update in Service Communications #2011-003
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Online Perazzimx14

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Re: Gas pressure building up
« Reply #6 on: January 14, 2015, 07:02:41 AM »
There was a Tech Update on 09-11 models for a free flowing canister valve PN 860138 it is blue & orange. Old valve is grey.   It is behind the LH throttle body toward inside.  The shop should have replaced it also. It will have no pressure in tank w/new valve. AND it's free from Guzzi.
Tech Update in Service Communications #2011-003

I am in the camp that believes that the tip over valve belongs in the trash. It should be replaced with a barbed coupling and the tank gasses can ebb and flow as the temperatures change.
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