I'm running a Suter Tigre 2300 on a perry pump and carb that runs very good. I only run a 16 X 8 prop and it realy spins it. I don't think it will spin a 18 X 8 very well. With 3D you will want good excelleration on the prop and I get that with a 16 X 8, but I don't think it will with an 18 X 8.