A flying club member was given a ys 110 and he started it and it backfired and through the prop.so he richen the mixture and it did the same thing. I have 3 110's and
have had that happen but not repeatedly like 4-5 times.He gave it to me and told me to be careful and good luck.The pressure adjustment looks to be flush with the casting
i will check the timing marks to make sure they are properly lined up and wait to here your suggestions. Thanks greg