SOHC.co.uk Forums > Other Bikes

CV carbs - how do they work?

(1/2) > >>

pae:
Think they're called CV - they're the vacuum type carbs fitted to a '85 Yam XJ600. As the Yam forum continues to be pretty useless with answers I thought someone here may have experience of these type of carbs as I've never played with them before, being used to a cable opening the slider, not a vacuum.

I don't have an airbox for my project and wonder if not having one fitted will affect the carb vacuum. I know it won't run great but just want to fire it up briefly, but will it run at all like this?

I've never worked with vacuum carbs before - what lifts the sliders up so I can squirt some easy-start in to the throats whilst it's turning over? Presumably it's a vacuum in the top of the carb bodies that lifts the sliders, but where does the vacuum come from? There are no hoses that connect up to the carb tops as far as I can see.

regards, Phil

matthewmosse:
I think it works by the air pressure difference created by the airflow thru the carb - things that go wrong, is the diaphrams can split / perish. I'm not a great fan of them myself but keep it all as is because they cann't be all that bad compared to trying to fit something else. In theory they should give better fuel economy and they should work ok with k&n s or probably with no filter. Have some on my bmw airheads. If the economy's worse with slide carbs I'm glad of the difference as the bike's not that economical.

SteveD CB500K0:
Here's a reasonable explanation:
http://www.bikerenews.com/Stories_Archives/Carburetors.html

Spitfire:
That's a great link, thanks Steve, same bookmarked

Cheers

Den

pae:
Thanks Steve, good link. Should all be OK then, will give it another go tomorrow.

Phil

Navigation

[0] Message Index

[#] Next page