Suzuki 70 80 & 90hp differance

[stormmnv]

I was looking at the specs. on a DF 70A Suzie and find that the 70 / 80 and 90hp engines appear to the same bore, stroke, weight, etc. the only difference is the hp. rating and price... Any ideas why the different hp. ratings.
Also, I cannot find any new ones for sale on the net like yame or Mercs????

 

[lakensea]

Different camshafts & engine management computers. Engines can be bought at and installed by your local authorized Suzuki dealer. The DF80A is not available in the US.

 

[jimmbo]

To make engines of different HP ratings with the same displacement, Improvement to the engines Volumetric Efficiency has to happen, more air and fuel in, more exhaust out. Camshaft timing changes move the Torque curve into a higher rpm range and results in more HP at higher RPM, and a slight drop in Torque at low RPM. Changes to compression, the induction and exhaust systems, timing advance curves and fuel delivery curves.
In other cases, an engine is derated by restricting its breathing ability.