I built one years ago . It still fly's well and is my go to "stunt" plane when the field or weather is a bit dodgy .Used for engine testing mostly now .
Mine has fuselage mounted gear for the grass . It tracks real well and has had a variety of engines .Fox .35 ,Enya SS .30 , Evo .36 (too much) , Brodak .40 plus others. Presently an old Double Star .40 resides up front .
It likes 62' to 65' lines depending on the engine and wind . The tank is a 4 oz. Hayes with muffler pressure . This setup gives very consistent runs with very little drama .
I like my Zero and would recommend it to anyone looking for this size / type of plane .
Brad