Carb Questions.

Hey I have a few questions. I just competely rebuilt my carbs off my 81 kz 650. and replaced the fuel lines that were already there. so, what are these nipple things supposed to be connected to i circled them in red..... pods are on the bike btw.

oh. and the black tubes that i connected to the carbs where they were when i got the biek...and i traced them back and they are connected to this ugly ass thing.. what is this? a breather thing? do i need it?

DestroyKC wrote:

Hey I have a few questions. I just competely rebuilt my carbs off my 81 kz 650. and replaced the fuel lines that were already there. so, what are these nipple things supposed to be connected to i circled them in red..... pods are on the bike btw.

This may help.

Good Fortune!

that does help alot. So the ones to open air are to that ugly ass filter thing. And then where do i run overflow tubes to? Just to like the bottom of the bike and let drip out?

DestroyKC wrote:

oh. and the black tubes that i connected to the carbs where they were when i got the biek...and i traced them back and they are connected to this ugly ass thing.. what is this? a breather thing? do i need it?

If that's a filtered intake for the two reed valve caps, may toss it, and connect the caps to each other with a hose between them (as shown below in red), or just block off each cap. The caps allow for air injection into the exhaust to help reduce exhaust pollution.

Good Fortune!

I have the same bike. The device under the tank is the Air Injection System - it injects fresh air into the exhaust ports to help burn off any unburned fuel that exits the engine. The manual has a test for it to make sure it works. It's fairly common for folks to get rid of it, but you might need to install block-off plates in place of the reeds. I don't know enough about it.

The top brass nipple in the first photo is the vacuum port for the petcock. Engine vacuum pulls open a diaphragm to allow fuel to flow by gravity. When the engine is off, a spring returns the diaphragm to the closed position to stop the flow of fuel (ON & RES).
PRI (prime) bypasses the diaphragm to allow fuel to flow - engine on or engine off.

The bottom brass nipple on the accelerator pump (1st pic) is a fuel supply line for the accel pump circuit. See carb photo/diagram above. It would be a good idea to test the functionality of the accelerator pump.

Also in the 1st photo, the black tubing is a vent. Those two should be routed over the airbox shoulders then snug fitted between the airbox & sidecovers. The left side has a tubing clamp on the frame. They should point down to keep water out of the carburetors.

The carb overflow tubing & battery vent tubing should be routed behind the engine but forward of the swingarm & away from the chain.

If the airbox is not installed, a filter similar to the one in the 2nd photo should be installed on the crankcase breather.... it's the ~4" round thing above the engine/transmission & kinda below the carbs. If no airbox, note what size the main jets are, then check to see if they are suitable for your air-filter/exhaust setup.