ORIGINAL: Hobbsy
Earl, if its OK here is another Russian 10cc engine, a Zeus, it had a smallish carb and as pictured has a small exhaust port. It however runs smooth and very reliably, the carb on it is a slightly larger Webra. This engine was so tight I thought I could not get it running but once started it ran well. After 3 hours run time it still does a perfect imitation of a turkey call when turned over slowly. I know, I know, don't do that, well I did and it didn't hurt anything. I broke it in on Fox 5% with 20% castor.
This engine has a high exhaust timing best suited for a tuned pipe.