Possible to use sunny crank for conversion??

I've been trying to get hold of a starstream or j125 crank without any luck. Scooter restorations have some SIL cento/sunny ones going cheap and I was wondering if I could modify one to use???

not sure on the difference in the sunny to j range cranks, but Paul at scooter restorations will.
the j125 and starstream cranks are different, you can't put the starstream crank in a lui casing, only a j125 crank, the opposite applies to a vega casing.

From what I can tell it's the length of the spline that is different on all of these cranks. I'm gonna buy a few off scooter restorations and see what I can do by grinding off the case hardening, putting some weld over the top and then machining it to match a 4 speed j125 one. They're only round 40 quid a pop so I won't be out too much coin if it goes tits up...

keep us informed of how it goes.

any news? Possible to make it work?

Hi, yes you can modify a Sunny crank. The differences are the Sunny ones are Full circle webs (Not an issue) & the rod on the sunny uses a 14mm small end, so no good for j125 pistons (the pin & rod lengths are the same). Also the shoulder on the drive side web needs machining back to take the wider Drive side bearing (4mm I think), see link https://lunaownersclub.forumotion.com/t515-will-it-work for a visual example. No issues on the flywheel side, just use the 3 piece mag & ancillaries  

Casa now do a Starstream Con rod kit & Cookie at Chiselspeed can do the Rod & shoulder mod. Hope this helps.....Steve

         

Starstream Crank Webs