Fuel Tank Evaporation?

[DaveP]

I've been working on the 1981 GS650L since April and the fuel tank has been on the bike since the end of July with a new OEM fuel cock. I haven't ridden the bike that much, but wanted to keep the tank full to prevent condensation and rusting. It appears that fuel is evaporating from the tank faster than I am burning it. At first I was concerned that fuel might be getting into the crankcase or leaking somewhere else, but that is not the case.

Is it possible that the fule is evaporating so quickly out of the tank? Fuel is treated with Sta-bil.

As a side issue, I considered disconnecting the fuel hose (new OEM) from the tank for the winter and running the carbs dry, but I couldn't get the hose to budge off the fuel cock. Any tips?

Thanks,
Dave

 

[chuck hahn]

Yes it does evap quickly and even faster in a heated space As for the stuck line, take some pliers and grip it just enough so they dont slip and give it a twist and break the seal. Set petcock on prime with some extra line and drain it into a can.

For the bowls. take a PVC pipe and cut it in half after gluing on an end caps..cutting the caps in half with the main section also and making a U shaped trough. Drain the bowls into the PVC trough and then dump the fuel into a funnel and into a can.

 

[tom203]

If you've been running with Stabil (marine formula preferred), no need to run carbs dry. Best to get tank off and store someplace where temp doesn't fluctuate much- this avoids condensation.i've had good luck with this for six winters. In spring, add fresh fuel, put petcock on prime and away you go.

 

[Steve]

You guys are going through a LOT more effort than I am, and I have had no problems with tank evaporation or condensation.

Typically, I double the recommended dose of Sta-Bil, ride down to the corner to fill the tank, ride back via the other side of the plat (about a 3 mile ride), then park the bike. I have never noted any "evaporation" from the tank, although the bowls do seem to run dry.

This seems to work with 5 of the 7 bikes in the stable (the only ones that are road-ready), not sure what I am doing wrong. :-k

.

 

[chuck hahn]

I dont do any of that Steve. He asked about evaporation and I gave him the answer I dont drain the bowls either..but i saw the PVC thing a guy made for doing it and passed that on as well. I just go and start the bikes once a week thru the winter and let them run for maybe 10 minutes..keeps the Berrymans B12 laced fuel in the bowls soaking at the jets.

 

[Brendan W]

You guys are going through a LOT more effort than I am, and I have had no problems with tank evaporation or condensation.

Typically, I double the recommended dose of Sta-Bil, ride down to the corner to fill the tank, ride back via the other side of the plat (about a 3 mile ride), then park the bike. I have never noted any "evaporation" from the tank, although the bowls do seem to run dry.

This seems to work with 5 of the 7 bikes in the stable (the only ones that are road-ready), not sure what I am doing wrong. :-k

.

You forgot to figure in the shrinkage of the tank in cold weather. It only looks like you're not losing fuel.

 

[DaveP]

Bikes are stored in an unheated/uninsulated shed. I will keep things as is and not drain the fuel for the winter which is what I have done in the past, just top of the tank with more stabilized fuel. Batteries are the only things that have been removed to keep inside. Reinstall the battery and away you go.

Attempting to drain the tank and carbs was more of a reaction to the evaporating fuel.

Thanks,
Dave

 

[Brendan W]

This is going to sound crazy but there are such things as dry leaks. Not enough to form a wet spot - small leaks in say a petcock can be continuously wicked away.

 

[Rob S.]

You forgot to figure in the shrinkage of the tank in cold weather. It only looks like you're not losing fuel.

I know something shrinks in cold weather...it's not smaller, honey, it just that some of my fuel has evaporated.

Yeah, that's the ticket.