Gas tank on borrowed time

[KCScooterdude]

I've got a 1981 GS550L. Great bike, but the weak point has been the gas tank. When I bought the bike it had a leak that we were able to plug with some marine grade caulking. A petcock rebuild was also in order. There is also something else wrong with the tank because I can't get even two gallons of gas in it. This makes for very short rides between gas stations.

Here's my questions

Anyone had experience with fitting an aftermarket tank on the their GS? I'd like a bigger capacity tank and maybe more of a cafe look to the bike.

Anyone know a good vendor should I decide to have the tank sent out and refurbed?

[KitKat]

why can't u get more than 2 gallons in it.

Is the tank bashes up so it only holds that much, or does it start leaking out of somewhere?

[duaneage]

honestly I would look for another tank. Bikes get parted out daily and there is bound to be someone with a better tank for you. I see you did not mention if it was repainted, I bet the side was kicked in and they filled it with bondo to paint with. Also. creme kits remove internal volume a bit and that may reduce the internal volume

[KCScooterdude]

The tank has never been painted. I imagine the previous owner tried to fix the leak before we got it stopped, so there's probably enough stuff in there that it has reduced capacity. My problem with getting another tank that's not NOS or a new aftermarket is that I could spend the money and still have to fix a leak, rebuild the petcock, etc. I'm prepared to go that route, but if I could find an aftermarket tank that would give me a bit more capacity I would prefer that.

[Joe Garfield]

I have the exact same problem! I have an '82 650L and it never takes more than 2 gallons to fill, even when I have to switch to reserve. I'm lucky to get 110 miles before a refill, and it's getting annoying.

I was hoping to find out if a tank from an 850 or something would fit my bike for more capacity. My tank has original paint and no liner, so I'm not sure where the extra capacity went

[Nessism]

I have the exact same problem! I have an '82 650L and it never takes more than 2 gallons to fill, even when I have to switch to reserve. I'm lucky to get 110 miles before a refill, and it's getting annoying.

I was hoping to find out if a tank from an 850 or something would fit my bike for more capacity. My tank has original paint and no liner, so I'm not sure where the extra capacity went

I'm about 95% sure no other tanks will fit without welding.

[SqDancerLynn1]

What you can do is when it hits reserve ? drain the tank into a container and see just how much fuel is available on reserve, best way.. Or hit reserve and continue riding until you run out, make sure to have a can of gas handy. You may go 50 miles on reserve ?? It is always nice to know how far you can go..

[neeko]

I'm having a similiar 1981 gs550lx tank dilemma in that I can't seem to find any other higher capacity tanks that would fit. Did you experiment with other tanks yet? I have 3 tanks sitting at home all with similiar mounting points but all of them are off when it came to dimensions.