78 kz650 carb question ??

I got this bike, 1978 kz650 B2, and it had nothing on the nipples on the number 2 and 3 carbs. I'm assuming these are a vent ?? Can these be blocked off, or do I need to run a vent tube off of them running down the back side of the motor ??

If it is a B2 then the carbs that came stock on it are Mikuni vm24ss carbs. If it is a B2A then the carbs that came stock are vm22ss carbs. Either way the bowl vents should be on carb #2 and carb #4.. They need to be open to atmosphere, so that there is atmospheric pressure on the fuel in the bowls. If they have a vacuum port it should be on carb #2.

Do the carbs have ribs on the upper carb body. Post a pic of the carbs, as some of the larger carb sets (vm26ss) carbs have the vacuum port on carb #3.

I have attached a pic of a set of vm24ss carbs showing the vent,, vacuum and fuel linlet locations.

I'll try to get a picture of the carbs posted tomorrow. There probably the bowl vents as you've stated, but I'd like to verify this so I know for sure.

Thanks gd4now !!

Forgot I had pics of my carbs. You are correct that it's carbs 2 and 4 that have the nipples / vent tubes.

Just to verify, they are vent tubes ?? Do I just leave them as they are, or should I run a tube from the nipples to the bottom back side of the engine ??

I'm concerned about dirt getting inside of the carbs.....





Thanks !!

If your bike still has the airbox you can run hoses from the 2 vents under the seat to the big opening at the top of the air filter. Some bikes came with the vent hoses running back under the seat and terminating next to the frame. Ed

Perfect !! That's what I will do. Thanks 650ed !!

kzrider.com/forum/3-carburetor/597187-critters#661716

I've always left them open...... I tried hooking a line to them and running them in between the swing arm and motor but it wouldn't run right at speed not sure if the wind was affecting it or not ........ was a long time ago.

Thanks !! I'll make sure I don't try that way then.