Chrysler 4 HP Outboard Motor Service Manual OB 2278, Page 5Get this manual
SECTION IIENGINE SPECIFICATIONS 4H.PHorsepower, OBC Rated EngineTwo Cycle Bore and Stroke Cubic Inch Displacement Cooling
5250 RPM 4750-5750 RPM One Cylinder 2.0" 1-916" 5.00 CuInWater Cooled Displacement Type Water Pump Aluminum Alloy 7-14" Dia 5-12" Pitch, Right Hand Rotation Champion L7J .030 .020 15" or 20" 38 lbsfor Short Shaft 110-125 PSI