Does it look like this?

http://www.supertigre.com/engines/supg0248.html

If so, it depends on how old the engine is as to what it is...it could be an old G-2000 20cc (1.2 cu in) or the later G-2300 which shared the same crankcase casting (23cc or 1.4 cu in). If you were told is was a 1.48, it's very likely the later G-2300 version.

Great engine but a questionable carb depending on the vintage. There are lots of threads about the carb mid-range problems in any number of forums. If you have the newer, more problematic carb, there is a fairly well-accepted fix if you feel up to Dremel-ing your carb or you can simply replace it with a Perry carb and pump/carb combination.

To identify which carb you have, remove the carb drum and look at the cam groove...if it's straight, it's fine, if it has a dogleg shape, it's the newer carb that produces a rich midrange.

Hope this helps...