Last weekend I purchased a box of stuff, from a non-modeler, in the contense of the box was an OS carb Marked 8B, it is made just like the 7D but seems to be a little larger. My question is does anyone know which OS engine this was used on?

Thanks
Don

Looks like it was used on 61-90 engines and the 7D is used on 91-108 engines.

The O.S. #8B carburetor was used on some high-output engines:

All O.S. Max engines: .61VR-M ABC, .61VR-M ABC, .65 VR-DF ABC, .77VR-DF ABC

The O.S. Max #7D carb was used on the O.S. Max .91FSR and the 1.08 FSR (BX-1)

I know this is an old thread, but I am in the market for an 8B carb.

Let me see of I still have it, I will get back in touch with you. By the way what does it fit?

I will machine the neck to fit other engines. I don't know what else it fits as is, it is the same carb as in the OS .77 VR-DF.