Parts index

A popular conversion for all the 125, 150 and 175cc Lambrettas around. Due to the differences in the crown height (distance between the gudgeon pin and the dome of the piston) you either need to shorten the barrel or put a longer conrod (Yamaha 115mm is ideal) into your crank. You need to use a 150 or 175cc barrel and just bore it out to take the piston. If you shorten the barrel to fit on a 107mm conrod then the inlet port will be approximately the same as a stage 5 tune. This piston needs shortening in this version. If you do not shorten the barrel then the barrel ports will stay nearly standard. You will need to reprofile the head to suit the new size piston. We can supply a new head already done.