Fuel Evaporation???

[Solina Dave]

Does anyone else notice a considerable amount of fuel missing from the bike after winter storage? My GL1000 is away for about 6 months. I realize that the fuel in the carbs evaporates, but is there a lot of fuel lost to evaporation from the fuel tank also? I mean maybe as high as 15 to 20 percent.
I always top up the tank prior to storage. I average pretty close to 50 mpg. However, on the first fillup of the new riding season, and only the first fill, I'm noticing a significant reduction in my fuel milege. As low as 26 mpg to 38 mpg.
All the fills after that have the mileage hovering in the 50 mpg. range, give or take.

I'm at a loss........................Dave

[dakotanator]

Just "woke up" Ginger ('83 Aspy) last week. Her tank was almost as full as when I put her away in November. Only about a 1/4" down the neck from the top I filled it up to.

[landisr]

You may have got some junk gas on your storage fillup, and combined with the stabilizer, just suffered through running it out of the system. If it's running good and your typical mileage has returned, I would just chalk it up as a Mystery Of The Universe.

I don't even bother checking mpg for the first tank or two of the season.

Ron in AZ

[newday777]

Rather than evaporation, I would suggest to be looking for a leak into the carbs and oil overflowed from a leaking petcock if you turned it off or if you didn't turn the petcock off, leaking float valves and thus getting a cylinder or more filled with gas and siphoned gas into the motor.