Mechanical (Piston valve) or Constant velocity carbs

[M0WBY]

Hi

Which are better Mechanical (Piston valve) or constant velocity carbs on a CB650?

I know the CV carbs are found on the later models and have mahosive main jets compared to the older mechanical carbs (92 vs 120).

But does later = better? Better performance? Better durability?

I know the older ones you can set the float height but the CV ones are fixed level floats.

Just wondering...

Cheers

John

 

[Bryanj]

Not 100% sure but i dont think you can just swop carbs as the spacing is different

[M0WBY]

Hi

I was not thinking of changing to them I was just wondering why they changed them. Just idle speculation... usually they had a good reason for changing stuff!

Cheers

John

[Bryanj]

Emissions for the US i think