Bob...My EVO didn't do it at first on 4 ounces on a tutor2,but after many flights it does fine now.powermaster 10 percent,10-6 zinger,10,500 rpm, stock tube muffler on pressure,medium venturia, 64 foot lines, stock rear needle set up etc.Iv'e got fifty five flights on it now and it only gets better.It pulls a Tutor 2 with authority just a little better than my la46 did.For the bucks the EVO is quite a motor....Jim Welch