Had an OS .61 fxhwc from a past heli project that has the new 60b 3 needle carb just sitting around, so I got to checking and after the insulator ring was removed, it had the same 15mm diameter neck as the stock 60f that the 1.60 uses. The thickness of the 60f neck is 2.75mm for a fair amount of material for threads for the 2 3.5mm screws that hold the carb to the crankcase. The 60b carb thickness is 2.5mm and by looking at it seems just thick enough for drilling and tapping for the 2 screws if you are careful not to mess them up. I found a m3.5x.6 tap on line yesterday and it’s on order. I marked the 60b neck where the holes will need to be drilled and I need to go out and buy a new sharp #32 drill bit before I can do anything else. In theory, this 60b carb should work fine on the 1.60 engine, it fits well and with care, the mounting method can be transferred to this carb. It’s my thinking that with a much more precise carb barrel and 3 separate adjustment points, the 1.60 should run much more consistent especially in the midrange without burble and without worrying about a lean run and overheating and it gets rid of the trouble prone remote mounted needle valve assembly.

Scott