78 kz650 hose mystery

I'm working in a bike that hasn't run tin years. Surprisingly, after cleaning carbs, electrolysis on a new tank, pod air filters and installing electronic ignition, it started up first try. Awesome.

The issue is I have mystery hoses that I don't know where they go. Can you tell me what I do with them?

Those appear to be part of the emissions system. They should connect to the vacuum ports on your intake boots

Hmmmm... There are two places on the bottom of the middle two carbs that are plugged. Meanwhile if I put my finger over either of these hoses, the bike dies. Looks like the long hose goes up toward the front of the bike on the hoses that run from the tank all the way back to the air box. I can't see anywhere the smaller one goes.

Meanwhile, I have no air box since I'm using the pods so that big hose just goes nowhere. Is this ok?

The thick hose that comes from the front of the bike should connect to your air box. Ive heard of some members taping the hose. If you aren't using the stock air box I'd recommend removing the whole emissions system to avoid any vacuum leaks. If you do remove them be sure to cap off the ports where the hoses were removed. Don't throw away any parts you remove because they may be useful later (especially if you're still tuning the pod filters)

kzrider.com/forum/2-engine/593212-79-kz1...bove-2200-rpm#627598
Look for Patton's replies to that thread. He has some pics of how the system works and how to remove if it that's what you decide to do

If that's an emissions hose someone has swapped engines or else your bike is not a 1978. The 1978 KZ650 had no emissions stuff. That stuff started in 1979. What indicated to you that the bike was a 1978? Ed

Hmmm... The sticker on the frame says 9/78

I'll check the thread. Thx.

How about the small hose?

AHA! That sticker shows when the bike was made, not what model it is. Just like Chevy and others start selling next year's cars in the Fall of this year, so too did Kawasaki start making the next year's models in latter part of the previous year. Your bike is a 1979 model. If you can post a couple more pics of the parts in question, including the places on the bottom of the carbs that are plugged and where the big hose is attached on the other end, we might be able to identify them. Ed

Thx, brother. Here you go....

Meanwhile, I'm also trying to get some smaller turn siglals for front and rear. Is there a standard option? LED?

In addition to below, there should be a port on the top of # 2 and #4 carbs. These are vents for the carb bowls and should have hoses that go from them toward open air - do not plug them up. The one on the #2 carb will be a little further toward the rear than the petcock vacuum port mentioned below. Ed

You are a stud!

Ok. One more ask. As per the pic, I attached a hose coupling between the center two carbs. I assumed it was missing. But after looking at some vids on you tube I'm not so sure.

Should I keep that hose coupling. or eliminate?