Real difference on a 150 between a 18 or 20 SH Carb ?

[Lor@n]

Is it worth changing a 18 carb to a 20 carb on a Lambretta 150 engine ?
Don't know if it's worth and if I'll notice any difference ?

Thanks for your help.

[Lor@n]

I assume no one took the hassle to do it.

[rog60]

Well as some seem to change a 20mm to a 22mm, and report some improvement I suppose there must be an advantage. I.ve changed from a 22mm SH2/22 to a bored out to 25mm Jetex and got an improvement on a Stage 4 indian lump/clubman. Not much though. a little more acceleration and about 2-3mph on 4th gear.

[Lor@n]

thanks