The Li 150 came as standard with a Dellorto SH1/18 and, imho, is better suited to the Li 150 barrel than the SH2/22 that you have fitted currently. You will need, however, a different manifold, one suitable for the 18/20mm carburettor. Getting a good SH1/18 carb may prove difficult as they are no longer produced (although a local Notts dealer has some NOS carb bodies). Scootopia do have new SH1/20 mm carbs which would work on the Li 150 barrel but you may have to do a bit of fiddling with the jetting as the Li barrel never had the 20mm carb fitted, although the SX 150 barrel did.
