Fuel Tap connections...

Hi all,

Can someone help and describe the connections from the fuel tap to the carbs please?

I can see on the tap the top back connection is the vacuum - where does that connect on the carbs?
The other two larger pipes are the main fuel supply and the prime - the main fuel connects between carb 3 and 4, but where does the prime go?

Thanks - Paul.

Should have added = the bike is a KZ650 E1 LTD 1980. Thanks.

Something is amiss.

Your KZ650 petcock should have a total of 2 hoses. One is the vacuum line that should attach to the nipple on top and toward the front of the #2 carb. The other line if the fuel line that runs from the petcock to the “T” between #2 and #3 carbs. There is no separate line for Prime. All Prime does is change the position of things inside the petcock to permit fuel to flow in the absence of vacuum such as starting an engine that has been sitting for an extended period.

So, if your petcock has ports for 3 separate hoses it is probably originally from a large displacement KZ that has 2 separate carb feeds.

Take a look at the 2 links below for diagrams. Ed

www.powersportswarehouse.com/p/Kawasaki#...50-E1-1980/070054C-9

www.powersportswarehouse.com/p/Kawasaki#...50-E1-1980/070054F-7

The pic below is hopefully like or very similar to the carb at hand (maybe absent the fuel pump).

Carb holders (connects carbs to engine) aren't shown in the picture, but each carb holder usually has its own vacuum port.
The four carb holder vacuum ports are used simultaneously when synchronizing the carbs.

Unused vacuum nipples, wherever located, should always be capped (plugged).
In other words, no vacuum port should ever remain open to air.
An open vacuum port creates a massive undesirable air leak.

One of the vacuum ports on one of the carb holders may be used to supply vacuum to a vacuum operated petcock. Which is usually done when the carbs don't include a separate vacuum port dedicated for supplying vacuum through a hose to a vacuum operated petcock.

Some carb designs have a vacuum port dedicated to the vacuum petcock. Which is another separate vacuum port in addition to the four vacuum ports on the carb holders. Unless used for a hose to a vacuum operated petcock, it should always be capped (plugged).
Such separate dedicated vacuum port should not be confused with vent nipples (usually two) that vent the float bowls and should exit via attached tubes to open air typically routed to exit underneath the seat or routed down around the swing arm to exit underneath the bike.

Here's an example of carbs with a hose connected to a dedicated vacuum port.



The following pic doesn't show the vacuum port located on the engine side of the carbs.


Good Fortune!