Newbie Carb Question

Hi All, please excure my ignorance, and answer in basic terms, but still getting to know my new (old) machine and get it running after a 12 year lay up (PO) I've cleaned the carbs and wa s putting it back together and notice it has a vaccum off above the main fuel line from the petcock, I don't remember removing one nor have I one knocking around the garage with the other bits I've removed. Looking at the manual it suggets a hose from there to the float bowl? but where abouts ('Haynes' manual didn't provide any pictures of that end.
Q where a bouts does the vacuum hose go to (a 1983 UK XJ 750) and where to source something suitable in the UK?
Pictures even better
Dumb Q but I have a missing cap on carb #2 between that and the engine that looks the same diameter where as the other 3 have industrial looking caps on- does it link here or have I just lost a 4th cap?
Ta muchly

 

The vacuum hose should go from the petcock to the 3rd carb vacuum port - the vacuum port are the brass nipples on the engine side of the carbs -- sticking up from the rubber -- carbs 1 2 and 4 should be capped with a rubber thingy w/an oem clamp.

 

shack- dmccoach is right on with the correct answer. But i gotta say, dont be afraid of sounding "dumb" or whatever when posting a question. That is what this forum is here for. Anybody whos trying to do his own wrenching on his bike has got my respect, & Im sure many members here will say the same. So ask away my friend, even the most experienced members here still need assistance from time to time. Good luck & ride safe.

 

Thanks for that, and I'm happy to sound a little dumb, so long as some of the information shared stays in (I did a little search before getting the heap and when I found you guys I felt happy enough to give it a punt as this forum rocks for XJ knowledge.

Right a couple more Q's

Routing the vaccum hose, where does it go and how long to I need to buy, I've had a little search for supplies on the t'interweb and haven't been able to locate a supplier so what size diameter hose and how stiff does it need to me (I read somewhere on here that it needs to be still enough to not close in on itself)

Finally and more fuel pipe related, I was going to get an inlie clear filter and wondered what sizes folks have been using and how they got on (again I guess I mean pipe diameter, length and where they have located it)

Thanks awfully 8)