Motorcycle Repair: Fuel cap set allows water into tank, 1991 suzuki gs500e, latex caulk

Question
Falcon,

I just bought a 1991 Suzuki GS500E, and I know nothing about mechanics and engines whatsoever. I'm having a problem where water is getting into the fuel tank when it rains, and I don't have a way to store the bike inside or the funds to buy a cover.

Water comes in where the silver (cap set?) meets with the tank body. I can clearly see there is a gap, though it almost looks as though this is by design. Water gets in there, and then accumulates in a small resivoir that, when it fills, falls into the tank itself. I know I could use some clear latex caulk (I'm good at fixing houses, not motorcycles, so let me know if I'm being ridiculous) to seal off the gap, but if it's there by design to allow breathability, then I don't want to do that.

When I close the tank lid, there is a rubber seal that ought to keep the water out. This seal would cut off the water resovoir from being able to fall into the tank, but water would still accumulate in the resovoir. It seems likely that this seal is worn and in need of replacement, but I don't know where to get a new one, nor how to install it if I did. I've looked online at sites such as bikebandit.com, but it doesn't break the part down enough. That site wants to sell me the whole fuel cap set for about $130.00, and I can't afford that, and only need a new washer.

Advice?

Thanks a million, Chris. I appreciate your work here.


Answer
Hi Dave.
 Unfortunately, it does seem as if the problem is the gas cap seal.  Check with a Suzuki dealership for a new one.  The worst part is that you have a suzuki.  They really stick you for parts on that make, so you will pay a bit more than if the bike were a Yamaha or Honda.

 Do not make a caulk seal.  It will not work properly.

Good luck.
FALCON