Can't really make out the detail well enough in that pic, I'm afraid.

The vacuum line fitting is on the top side at the inboard end of the intake spigot [this is the tubular bit that sticks out of the side of the barrel/cylinder, which the carby mounts to]. It was only used with the G3 carby, BTW - earlier models didn't have decompressors.

Like the one in this pic, with the vac line on it:
[Linked Image]

Cheers,
Gadge

"ODK Mods can explain it to you, but they can't understand it for you..."

"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."