ANOTHER good reason to hate RNVs! At least on the OS .46 FX, the RNV (and tube) get in the way of the engine mounting screws. But I don't understand why the zip ties didn't take care of the problem.

I've had little bubblies with my OS .46 FX. I put really clear tubing between the tank and the needle valve, and the bubbles were definitely coming from the valve, not the tank. But it only happened when I accelerated quickly from idle to full open, so not a big deal.

Since the needle valve that goes into the carb seems to be exactly the same as the needle valve that goes into the RNV, with the exact same O ring, it would seem to me that both probably suck air exactly the same, it's just you can't see it with the carb-mounted NV.