Dellorto SHA: 15mm or 16mm, why?

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DanielMaia

New Member
Jun 24, 2009
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Portugal
HI guys!

Im thinking in buy one of those little great upgrades, but...the question is, 15mm or 16mm, and why?

Both fits on the stock intake, right?

thank you
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
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living the dream in southern california
as far as it being too large, the stock NT carb without the fuel shut-off is supposed to be 13mm, and the NT with the shut-off, as well as the NT "Speed" carb are 14mm. i think the "Speed" carb claimed 3mm larger bore, making it 17mm, but mine isn't. it's the same except for saying "Speed" on it. i dunno what the CNS is.

also, these measurements seem to vary from carb to carb, probably due to poor quality castings, or if you got the first one from the mold or the last one before cleaning it.

on my heavily modified 66cc Grubee GT4, i'm running a 16mm Mikuni and it works great. even without the other mods, it'd probably still work good, but i have no way to know for sure, short of building another bike and trying it.

my carb has a flange mount, not a spigot mount, so i had to make my own manifold.

i don't think you'll notice too much of a difference between a 15 or a 16mm carb, but if you're planning on extensive mods, i'd go with the 16mm. it'd be easier to jet it down if it's too much carb, then trying to get more out of the 15.

there's a lot of people here who've used the dellorto's, just use the search bar up top.

sorry, can't tell you if it's an exact fit, but i think i remember people saying they've had to shim the spigot to make it clamp tight enough, but i'm not sure.
 

DanielMaia

New Member
Jun 24, 2009
309
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Portugal
Just arrived a 16mm Dellorto SHA,

What i first noticed is that it need a lower gigleur, for the optimum air/gas ratio, maybe the consumption is reduced a bit.

The gain in low rpm is really improved.

I will test this carb in the next few days!