I just got a YS .63, and it is my first 4 stroke engine. I would like to know if there are any "tricks of the trade" for breaking this engine in. I would also like to know what needle valve setting you ultimately arrived at for optimal results. I am running PowerMaster
20/20 fuel through it. It seems to guzzle fuel, but probably because it is way too rich now. It seemed like I went through 12 oz of fuel in 6 minutes.Joel