Hi All, I have an old Kawasaki Kx  with the same or close enough to the same carb in the picture, but mine doesnt have the black tubes. Are these just for the overflow on the float bowl or are they for something else? Thanks in advance, Aaron

The lower tube is the float bowl overflow. If the bowl over fills, it'll pour over a vertical tube within the bowl and out the pipe. It also works as a breather for the float bowl, stops a vacuum being created in the bowl as fuel is sucked out.

The second one on the side is a breather/balancer, it evens out the air pressure inside the carb, again fuel pouring into the bowl and being sucked out again tends to create a vacuum if it's not open to air entering.

Some carbs on the inlet stub or on the manifold might have a further pipe that would have attached to an autolube, a system of metering and pumping oil into the engine instead of premixing the fuel. It there was one and the pump has been removed it'll need blocking up.

Over the years most of these overflow/breather pipes get broken off or lost, simple enough to replace with a bit of tubing, that'll stop the naked barbs blocking up with muck.

 

Edited December 12, 20187 yr by goudrons

Dont run the float bowl breather up above the carb as this will cause flooding. Make sure that pipe gets routed down to place where it cant get plugged with mud etc. Clear tubing is better as you can see whats going on. The other breather/vent tube can be routed up onto the frame out of harms way, but put a bend on the end so the the tube end is facing downwards, this should stop water getting in if wading the bike through streams etc. ?

Ok Thanks for the tips guys, much appreciated?