2 stroke engines require oil to be mixed in the fuel and a separate oil is needed for the transmission.  We found a lot of people asking us what kind of transmission oil should they use in old vintage Husqvarna motorcycles (prior 1988). 

For the older vintage Husqvarna motorcycles, it's recommended that you use regular 30 wt oil for transmission fluid.  Any straight 30 wt engine oil that is not synthetic will work perfect.  It does sound basic but remember that the clutch plates were made a long time ago when all they had was straight 30 wt.  The modern oil of today has additives that will clog the pores of the vintage clutch plates causing severe clutch slippage.