l own a 2008 Lambretta Uno 150 scooter. About every other time l ride my scooter, the acceleration will hesitate when l turn the throttle. Any idea what could be causing this to happen?

well first of all, lambrettas are not a very good brand. Vespa and honda is better. And second of all, the fuel could be old so it might have gummed up and that could be stopping it, or it could be the wire that controlls that throttle needs tightening. l think the latter is more likely. This happens with my moped when l ride it in cold weather so that might be causing it, its october now.

Answering this question requires more information.

When does this hesitation occur?
Off the line, accelerating from a stop?
When accelerating after coasting?
After a large deceleration (braking?)
First thing in the morning but not any other time?

Many many miles (km?) on the bike?
Did you buy it new?

Do not hesitate to use something like SeaFoam engine clean, in the right amount, a couple times a year. If the hesitation is at speed, make sure the air cleaner is clean. An engine operating at say 50% of max may be already starving for air & when u ask it to suck more air in, like when u open the throttle, it just can not do it.