St tank for g/s

[berndt]

A friend has a st tank I'd like to fit on my 84 g/s but it looks like a different gas cap. Is there an adapter or way to put a screw it in gas cap in an st tank?

 

[52184]

The ST tanks use the same flat gas cap w/flip up handle that was used on all the BMW bikes those two years. #5 in the picture below.


If the tank you are looking at has a raised lip, it’s not an ST tank.

Best,
DeVern

 

[6322]

The early R80GS had a different filler cap than the ST. The difference is how they vent. The GS had a vent tube coming from the cap. The other airheads including the ST vent through the cap without the exposed hose. I went the other way and put a R100GS tank on my ST.

 

[berndt]

https://photos.google.com/share/AF1...?key=TTdSTmVCaldpdkJORjhQYnNvbEFRUUtnVHhQT0N3

this is the tank, I was just curious if I could put a cap with a hose breather on it.

 

[6322]

I don’t think so.

 

[pglaves]

https://photos.google.com/share/AF1...?key=TTdSTmVCaldpdkJORjhQYnNvbEFRUUtnVHhQT0N3

this is the tank, I was just curious if I could put a cap with a hose breather on it.

Why?

 

[berndt]

I just thought that was how the original small tank g/s was.

 

[Visian]

The early R80GS had a different filler cap than the ST. The difference is how they vent. The GS had a vent tube coming from the cap. The other airheads including the ST vent through the cap without the exposed hose. I went the other way and put a R100GS tank on my ST.

My 1986 G/S had the PD kit installed by the dealer, so I got the stock tank (plus other parts) when I bought it.

The stock tank has a screw-in cap and only one petcock. Kind of a lightweight mechanism (both cap and tank neck).

The PD tank has mechanical quarter turn cap onto a much sturdier tank neck, but vented by rubber hose to the atmosphere.

 

[6322]

This is the original configuration for the early GS: