Motorcycle Fuel-Tank Question

[Weazel]

Hello,

I've got an '82 Suzuki GS-650. 4-cyl, 4 carbs, and theoretically a 5 gallon gas tank. Unfortunately, I'm only able to get 120 miles or so before it starts to sputter and I have to go to reserve. I thought it was bad mileage, but then when I go to fill it, the tank only will take 2.5 gallons or so before it's pouring out the top.

So basically it seems like I'm only able to use half my tank capacity. The tank does not appear to be split, as there's only one switch on the left side for normal operation, reserve, and for priming. The tank is tough to see into, but it's definitely not split. I am not 100% sure that it is the stock tank, but it sure looks like it. It definitely looks like it should hold more than 2.5 gallons.

Any ideas? Should I just run the thing on reserve and see what happens (besides me getting stranded)? Should I switch it to "prime" next time I fill up? I'm kinda annoyed with my 120 mile range, and would really like to find out what is up. Thank you very much!

 

[Buick From Hell]

Weas, according to specs you have a 4.2 gallon tank, so "running out" at 2-1/2 gallons is typical! Means you have a pretty decent reserve!

 

[Weazel]

Hey BFH, thanks for the tip! I had checked www.bikez.com and it was saying 5+ gallons for my tank capacity, but I couldn't remember what it said in the Clymer's manual. I'll double check that after work, and if it is in fact a 4.2 gallon tank, sputtering at 120 miles would make a lot more sense. I was just worried I had some blockage in the tank somewhere, but that doesn't sound like the case. Thanks again, I feel better about it now.