Do I need these?

Another dumb question by a newbie. These aren't my carbs but when I saw this photo, I remembered that my carbs don't have the tubes off the accelerator pump as shown by the red arrows. Aren't these necessary for the bike to start?
What do the green and yellow tubes go to?

On those you do.

btkz650 wrote:

Another dumb question by a newbie. These aren't my carbs but when I saw this photo, I remembered that my carbs don't have the tubes off the accelerator pump as shown by the red arrows. Aren't these necessary for the bike to start?
What do the green and yellow tubes go to?

The accelerater pump pumps fuel through those tubes to the squirters in each carb. Here's the rest...

btkz650 wrote:

Another dumb question by a newbie. These aren't my carbs but when I saw this photo, I remembered that my carbs don't have the tubes off the accelerator pump as shown by the red arrows. Aren't these necessary for the bike to start?
What do the green and yellow tubes go to?

yellow and green are vents and you need the red ones to run fuel to the pumper.....

After installing the accelerator pump tubing between the carbs, you can test its functionality by vigorously actuating the throttle pulley & checking to see that fuel squirts out the pump nozzles without hitting the carb bore walls. If the fuel squirts crooked or dribbles out, then you'll need to investigate - it could be that something is clogged or the acceleratro pump diaphragm is messed up or something.

The carb vents should be directed down & away from the engine so that they don't let water into the carbs or get melted.

Here's a pic of oem carb vent hose routing to open air underneath the seat on a KZ900. (Oem hose color is black.)

Some owners prefer routing carb vent hoses to open air underneath the bike, perhaps alongside overflow hoses.

Good Fortune!

[Click on image to enhance view.]

Got the carb thing figured out. Thanks everyone.