I've began working on a HB twin. Does anyone know if parts are interchangeable with the HA model? The fuel system is filthy. I'm cleaning the lift pump, filter housing, and all of the lines. I'm impressed with the individual injector pumps and the copper lines. This engine design is well thought out. If she fires and runs good, would it be wise to replace the rings, bearings, and have the valves lapped? I hope to buy a CS engine as a primary and keep the HB as a back up.
