Flat slide vs round slide carburettor

[Tex]

In a few words (keep it simple for me please!), what is the advantages/disadvantages of flat vs round?

Is there any benefit to adding a flat slide carb to a bike that came with a round slide item?

Thanks
Tex

Apologies if this has been covered before, I did a search but couldn't find exactly what I wanted...

[mx250]

In a few words (keep it simple for me please!), what is the advantages/disadvantages of flat vs round?

Ads; Higher air speed over the venturi giving better more precise atomising which give more hp everywhere, better economy and better response.

Disads; None other than you can't use them on VMXers pre 1980 (or some similar date).

Is there any benefit to adding a flat slide carb to a bike that came with a round slide item?

Yes, as above.

That's the muggins answer , over to the experts .

[Lozza]

Basicaly the H section of the flattie seals better at the sides and there is less area under the slide.The less area creates less turbulence downstream, as Graeme said higher velocity/better throttle response. Is there a benefit depends on how it's tuned, I helped a bloke tune a flatslide(PWK) on a RMX and he went back to a semi flat(PJ or was it the other way around?) because it was (for some reason) too responsive on the throttle

[LWC82PE]

yes its pointless having a poorly tuned flatside as it could be no better than a well tuned roundslide

[WillsRD]

G'day All,

My '83 DR500 is fitted with a CV type carb, according to info on the web it should be a round slide. How does the CV compare with the round and flat slide? The bike will only be used offroad. Which one makes for easier hot/cold starting, assuming tuning is right?

sorry for hijacking the thread!

cheers

[Lozza]

My understanding is a CV is a 'road' carburetor, with engine vaccum lifting the slide, makes it 'smoother' I suppose.They are not used on proper two stroke engines so I have no interest in them, I just pulled them off, changed jets and needles on a mates gixer when he raced it.