Fuel Line & Petcock Hoses

[Gumbo76]

I have a quick Question. Does anyone know if I am supposed to have a hose connecting to the nipple on the backside of the Petcock? There are two places to connect hoses to it. The bottom one is for the Fuel Line, but I can't figure out if I am supposed to have a hose connected to the other one. I see nothing on Bikebandit's schematics for a hose that goes there. I can't even find one in a manual. Any Clues? I would appreciate the help. Thanks!

I'm trying to attach a pic so that you can see what I am referring to. It is to the Right of the Number 8. Thanks.

[gearhead13]

There are two nipples on a stock petcock, the bigger one is fuel to carbs, the second (smaller) one gets connected to the #2 carb for vacuum. The vacuum opens the petcock when the engine supplies vacuum while running. Your pic is pretty small, cant make out the numbers.

[tas850g]

on my '79 850 the small nipple connects to the #3 carb for vacuum. That's with the VM carbs which was last used in '79. As you may know the '80 and newer switched to CV carbs and i know little to nothing about those.

[BassCliff]

Hi Mr. Gumbo76,

Check out this page on my website:

Where Do These Hoses Go?

I'm sure you'll get it figured out. Yes, the VM carbs (~79 and earlier) have the vacuum connected to the #3 carb. The CV carbs (~80 and later) have the vacuum connected to the #2 carb.


Thank you for your indulgence,

BassCliff

[Big T]

#3 carb is the vacuum attachment for sure on VMs

What is attached to the nipple on the inside of your #3 carb?

[Gumbo76]

#3 carb is the vacuum attachment for sure on VMs

What is attached to the nipple on the inside of your #3 carb?

I'm not sure what is attached to the INSIDE of the #3 carb, but I have Hoses coming off the bottom of Every Carb. So, If I get it wrong what will happen? Anything? Mine is Definitely a Pre-80 Engine, but how do I know if it is a CV or VM carb?

[Gumbo76]

Hi Mr. Gumbo76,

Check out this page on my website:

Where Do These Hoses Go?

I'm sure you'll get it figured out. Yes, the VM carbs (~79 and earlier) have the vacuum connected to the #3 carb. The CV carbs (~80 and later) have the vacuum connected to the #2 carb.


Thank you for your indulgence,

BassCliff

Bass, as always your knowledge and Insight has helped out tremendously! I found my manual on your website too. is that a recent addition? I don't remember seeing it there before today... although I haven;t looked at your site in a month or so. Anyway, thank you so much for your help. I certainly appreciate all the help!

-Gumbo

[chef1366]

There is a nipple for a hose on the #3 carb. This is where the smaller petcock line is attached. It points up and is not at the bottom of the carbs. If you don't have a nipple on that carb the carbs are not stock and you need a mechanical petcock.