Gas Tanks

[gonzomn]

What year gas tanks had single petcock & what years had dual?

Thanks,

Scott

 

[manofsteele]

Well I can't cover all the years but I can tell you that my 79 had dual petcocks and my brothers 80 had a single.

 

[650Skull]

For what it is worth. I think all tanks up to and not including the 1980SG, and maybe the 1980G Special2, had dual petcocks. the petcocks changed, Vacuum and non Vacuum, so some will not interchange with different tanks.

 

[gonzomn]

Thanks,
When does a vacuum & non vacuum petcock need to be used?

 

[bluebikerblan]

Good question....especially since with age and consequence of failure a real mess, hazard and even engine loss can ensue from a leaking shut-off of the vacuum petcock.

A manual shutoff petcock seems to me to be the way to go whether by converting the vacuum type to manual with (an OFF position) or by purchasing the non-vacuum manual replacement.
ie....I have no good argument FOR the vacuum operated petcock as I prefer one with a
maually selected "OFF" position. Moreover the engine don't know or care. Blue