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NewB to Vulcans
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Discussion Starter #1
The bike stinks up the garage and then the house after I shut off. My commute is 70 miles with lots of freeway so she is nicely warm.

There are no obvious leaks I can find, not even a damp spot.

Since I have owned her I have rebuilt carbs, replaced the boot clamps, new petcock, new gas lines, new vent lines. She is marbled and the spare vacuum line capped. Gas Cap vents have been cleaned.

I am stumped, thinking of dumping some swimming pool leak finder dye in the tank to see whats turns red.

Any thoughts?
 

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If you let it sit outside until it cools off and then bring it inside, does it still smell up the place?
 

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If it's not just hot as Thorn asked... a hot bike can smell gassy, they get hotter just after shutdown.

Could be the petcock leaking through the vacuum line. Is the vac line wet inside or is the vac port at the petcock wet after sitting? Does the oil get overfull and have a strong gas smell? Does the shifter get sticky at the end of the ride?
 

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Hi Tony, my current bike does the same thing. I cannot locate any leak or seepage. I had purchased a 1989 VN750 years ago straight off the lot (long since gone), and for some reason I cannot remember it stinking the way my current used 2004 does. The only think I can think of is the venting that comes off the tank when the engine is hot. I have just got into the habit of parking it outside or cracking the garage door a bit for a couple of hours after a ride.
 

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Alpha Geek
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If it's fumes venting from heat soak after parking, it'd be worse with an almost empty tank than a full one. It could also be a leaky float valve although I think you'd notice that. Does it run fine? Ever have trouble starting? Gas smell in the oil?
 

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NewB to Vulcans
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Discussion Starter #7
AHA!!

It was quiet in the garage today and I was running in and out a lot fixing an intercom issue . Noticed a hissing noise that i thought was the water softener next to the bike, on closer inspection it was coming from the gas cap. When you get real close the hissing has some bubbling too. Bike was toasty after an hour running in 90 degree weather and gas tank was very warm and more than half full. So I found the source of my gas smell as there is gas around the cap.

Found a bunch of threads related to POOGS fixes discussing issues with the gas cap vent valves getting dirty/stuck/old and stiff (does that sound like someone we know?) so it looks like a gas cap dismantle is in my future.
 

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AHA!!

It was quiet in the garage today and I was running in and out a lot fixing an intercom issue . Noticed a hissing noise that i thought was the water softener next to the bike, on closer inspection it was coming from the gas cap. When you get real close the hissing has some bubbling too. Bike was toasty after an hour running in 90 degree weather and gas tank was very warm and more than half full. So I found the source of my gas smell as there is gas around the cap.

Found a bunch of threads related to POOGS fixes discussing issues with the gas cap vent valves getting dirty/stuck/old and stiff (does that sound like someone we know?) so it looks like a gas cap dismantle is in my future.
Hissing from a hot gas tank is normal and means that the pressure relief portion of your gas cap vent is working properly. The hissing is the release of excess air pressure caused by expending fuel (heated by the sun, engine, or fresh gas from a cold underground storage tank). So, this does not sound like POOGS.

POOGS is a situation where the gas cap vent cannot breath (intake) due to blockage. This usually results in a vacuum created as the fuel level drops in the tank and no air can enter the tank to displace the falling fuel level. That vacuum prevents the gravity feed of fuel to the carburetors at approximately 1/2 tank, engines starve for fuel, stall. Open gas cap, relieve vacuum, close gas cap, repeat.

I would still clean the gas cap as a preventative measure. However, it may not solve your problem as the small amount of vapor escaping from the tank should not cause enough gas smell that can reach throughout your house, unless the bike never cools down and the fuel continues to be heated and vaporized (e.g., parked in the sun). There is a small silicone valve on the exhaust port of the gas cap vent that you can verify is still soft and functioning (follow the gas cap vent channel to the very end), but the port it closes off when there is no pressure in the tank is tiny (hence the hissing).

Another option is to park the bike outdoors, in a shaded area, until it cools completely, then move it into the garage. If you still smell gas, then you have a problem other than POOGS (after verifying the silicone gas cap valve is intact). Also, send your wife out to walk around the garage. Women generally have a greater sense of smell than men. She might be able to pinpoint the source.
 
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