vaccum lines

I'm new to motorcycle ownership and have a question about my carbs and petcock. I have a 1982 KZ750N with Keihkin carbs. I believe I need to run lines from the black nozzles in between the carbs back to the petcock. The petcock is vaccum operated, I think, because it has two ports. Should the lines running from the black nozzles in between the carbs be joined by a T and ran to the petcock, or does 1 black nozzle get tied into something else, while 1 comes back to the petcock? When I got it started the RPM's were at 6K and wouldn't back down! I've checked the boots and they look ok, I'll try to clamp them better than the old springs that are on there now, and check them once I can get the RPMs down.

New to the site and have learned a lot already!!

Thanks in advance for helping a new guy out!!!

Hello, brentsspectre, and WELCOME to KZrider!

Here's some carb connection info:




Any still existing "clean- air" paraphernalia may be removed and shelved.




Good Fortune!

So the nipples on carbs 1 and 4 are tied into a vacuum switch?? Can they be capped? Where might the switch be?

Thanks for the info!!

Part # 6 is the "Vacuum Switch Valve."



Many bikes have already had the clean air stuff removed.

Be sure any unused vacuum nipple is capped/plugged (to prevent an air leak).

It's also important that the two nipples which vent the float bowls exit to open air.
This is usually accomplished by a hose attached to each vent nipple, which hoses exit to to open air underneath the bike, or sometimes exit to open air underneath the bike seat, or possibly exit into the air box.

Good Fortune!

The one and four vacuum ports go to the clean air stuff mentioned by patton. If you remove the clean air stuff (or if it's already gone), just cap those, so you'll have 3 capped ports, and the one still going up to the petcock vacuum.