Funnily enough, I ran across a Velosolex twin yesterday, and years (many years) ago, a French shop made a 100cc V twin Mobylette with a shared crankcase. When asked about efficiency, the builder admitted it was dreadful, but hey! It's classy!
Maybe my favorite drink would help! A Mason Quart Jar 1/2 filled with Kaopectate and the other 1/2 Milk of Magnesia. It helps sometimes, but usually just confuses me.