piaggio zip torque spring nut what size is it

just stripped the zip down to fit my malossi multivator and when i came to doing the clutch side the large nut behind the clutch bell , i cant seem to find a socket what fits its definately 33,34 or 35mm can anyone tell me for certain what size it is

 

38mm. I had to buy a socket especially for it as I didnt have that size at the time I needed it

 

mine must be different as its a mk1 zip, today i took a chance and bought a 34mm socket and it fits , just fitted 6 gram rollers and white torque spring out of the multivar kit and its terrible it struggles to pull of should i have left the standard spring in instead of the uprated one ,

 

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