Bukh V8 Series Owner's Manual page 343

Exhaust Hose Routing
General Information
All exhaust systems have some restriction to flow, or what is called "exhaust back pressure", but this must remain
at a minimum. The power output of an engine is directly related to the amount of exhaust that can flow out of the
exhaust system. For example, engines will generally suffer approximately a 10 horsepower loss for the first 1 psi
(7 kPa) of exhaust back pressure.
Exhaust Elbow Height
A - Measurement Between Straight Edge And Top Of Exhaust Elbow
B - Measurement Between Straight Edge And Water Line
Measurement Raiser to waterline = B - A (Minimum 330 mm)
Owners Manual 343