Is there a difference between?

[Lambo]

Is there a difference between series 2 and 3 crankcases? The casing on my LI125 special are damaged, a crack in one of the transfer ports that goes through to the mag housing flange, a snapped casing stud that looks like somebody has tried to drill it out and snapped the drill bit off and some damage to the drive side bearing seat. I'm thinking of just buying a different crankcase as it will probably be cheaper than getting mine repaired. I've been offered an li150 crankcase but i think it's a series 2 the first two digits of the engine number are 85,

Thanks

[johnnyXS]

well I'm currently doing the same thing .
I am building a series 2 engine for my series 3 scoot and will be transferring everything from the series 2 crankcase into the series 3 case as the series 2 case is fubar !

as far as I've read in Sticky's manual and advice from some Lambretta specialists everything is transferable although there are a few differences
The S2 has the same size studs all round whereas the series 3 crankcase has two larger studs for the exhaust which is an improvement but you could always drill and tap the 2x stud threads of the series 2 case
The engine mounts will be different of course but you can use either the S2 narrow engine bolt and blocks or S3 wide bolt and silent block mounts .
Thats all I am aware of .

Sticky's manual page 62 has a crankcase ID chart which shows numbers beginning with 85 are LI125 Special which makes that crankcase a series 3 so the engine number should run 125LiS 854198 to 867376
The only engine numbers I can find beginning with 85 are the SX200 big block and the 125 Special . I can't find any reference to a 150 crankcase beginning 85
http://scooterlounge.com/lambretta/reference-library/index.shtml

[Lambo]

Thanks for the reply Johnny, I did look at the chart in Sticky book and it does say that the first digit on an li150 series 2 engine starts with 8-9 and I can clearly see that li 150 is the prefix from the photo, that's why I thought it was a series 2 engine casing. Maybe I'll hold out for a series 3 casing, I think I'll put something in the wanted section, thanks again

[johnnyXS]

Looks like its a 1960 series 2 Li150