piaggio rolling nut 125 2t engine, either air or water cooled. Tried and tested, lots of tuning parts available, makes from 20 - 35 bhp depending on the state of tune.
Sources of a LC two stoke engines would be Piaggio Hexagon 125-180 and Gilera Runner/ Italjet Dragster 125-180, great engines even standard and as previously mentioned- mountains of tuning goodies Paul
Dragsters have been hard to find, and I'm struggling to work out which runners are 2t or 4t. Was there a year when they went 4t or were both types produced in tandem?
Try lambretta autos on Facebook.
Or lambretta innovations website.
2t engines are most peoples preference. A few people are using 4t engines now though.
If its for a lammy auto conversion it would be a lot easier to use the air cooled engine, thats what i did when i built my S2 auto, no need to worry about radiator positioning, routing water pipes etc. They are only a couple of bhp behind the lc equivilant and 25bhp is still easily attainable.
The a/c engine was used in piaggio typhoons and the aprillia sr 125's.
Try PSN scooters in Batley, they might be able to hook you up with something.