DL125 with Imola 186cc kit
Some people like some extra power for their classic scooter, especially when it is used in modern traffic or for long trips.
There are a lot of different options for tuning a Lambretta 4-speed LI series engine. It can start for example with a big bore exhaust (clubman) and go as far as a hydraulic operated 6-plate clutch. On the LCGB site there is a nice tuning section which can give you a general idea of the possibilities and this overview at Cambridge Lambretta
Here underneath you’ll find a photo review of a DL(GP) 125 scooter that has been upgraded with a Imola kit and some other relevant options. Here in Belgium there are no shops specialized in Lambretta tuning, so remember, you’re on your own. The legendary TS1 kit has his reputation with the tuners but you need a 200 block to fit it on. When you have a small block like 125/150/175, then a ready available kit like the Imola is valid option and gives as much fun.
1999 saw a prototype of the Imola cylinders, in the UK the first showing came at the Euro Lambretta Jamboree in Durham 2000.
Cylinder V1 1999 These came with a recessed inlet reed mounting, initial pre production kits came supplied with a GOL manufactured piston. These were subsequently recalled and replaced with a piston specifically made for the Imola. Initially the reed block gasket was paper, this was then replaced by a much thicker rubber version early 2001.
Cylinder V2 June 2001 This was updated to allow the reed block to moved further away from the cylinder. Transfers were improved by both adjusting opening and duration timings, and adding more material for use with further tuning.
Cylinder V3 April 2002. Exhaust and inlet, and transfer timings were changed, improving power output and derivability.
Cylinder V4 Sept 2009. Inlet finger port elongated, and transfer timings were changed, central combustion chamber head, seven stud fixing. Out of the box power using a JL4 is now 21bhp!
Ultimate Version August 2011. New larger reed valve assembly. Out of the box power using a JL4 is now 22+bhp!