honda 75 into 90 hp

[jim waddell]

got a 75 hp honda, all the specs are the same as the 90hp model. there has to be a way to get 90 out of the 75. someone told me there is a restrictor plate in the intake and the tuning is different. are the cams the same? also have a 9.9 honda and it is the same as the 15 (same situation?)

 

[Silvertip]

Re: honda 75 into 90 hp

The only way you will know is to compare the parts lists for both engines. any part number you find different is what makes them different. Because displacement is the same does not mean the rest of the engine parts are the same. Chevy built a 350 cubic inch V8 for decades and there are a dozen or more HP ratings for that engine. While some outboards used a restrictor plate or gasket behind the carbs, that generally is not the case with larger engines. On four strokes, the cams, compression, carburetion (or FI), exhaust, intake tuning, and now with the newer engines, the ECM gets involved. Parts cost generally makes it cost prohibitive.

 

[Skinnywater]

Re: honda 75 into 90 hp

The intake valves/cylinder head/camshaft/ECM are different between the BF75/90.

The camshaft/mainjet is different between the BF9/15.