1973 Potter with 115 Johnson - Prop Sizing?

[eggsuckindog]

Thats exactly what I was thinking when I read the title, I had an inline 115 Merc on my 18 with a 17 so sounds about right. That V4 does have much more torque though and if the engine is high enough it might swing a 17 to about 5200 RPM, I would see if you try something first.