RE: BELRAY MC-1
I have never used HR-1 which is primarily designed for power valve engines, but it has been my experience that while using other quality oils prior to switching to MC-1, the fuel consumption of my engines have remained pretty much the same with no marked difference either way.
If using MC-1 in your Suzuki racer made it perform to your liking, then more than likely it will give similar results when used in your model engine.
Karol