I am presently building one. Called DP and talked to Dave. Told him I wanted to put a Moki 1.8 on it. He almost fell out of hi chair. After talking a while, and stating I wanted to stay 2 stroke, he recomended either OS 160 or the Moki 1.35. I went with the Moki. Since I really like my other one. In 4 stroke he likes YS 120. Don't know if this helps or not. I would think alot depends on what you already have.