I have a os 40 sr engine i need the front crankcase for where the carb. goes in can you still get them from os ?

We're sorry, but parts for the O.S. Max .40 FSR have not been available for a number of years from us or O.S. Max, in Japan. The engine's been out of production for too long. You'd have to check with those hobby retailers who advertise in the model magazines as working with engine collectors. Also check the the swap shop areas, here on RCU.