How do you verify HP without tearing down engine?

[Stiletto444]

I have a Honda 15 (it was bumped up to 15 from a 9.9) How do you verify this with out tearing down the engine and checking what was replaced? I did not have the engine before the change so I do not have a comparison.<br /><br />Clay

 

[JB]

Re: How do you verify HP without tearing down engine?

It matters very little, Clay.<br /><br />Many think that changing the carb adds 50% to peak hp, but the bottom line is displacement and rpm. I do not believe the legend at all.<br /><br />Since the displacement is the same you probably wouldn't notice any change in performance except at WOT.<br /><br />You probably have a 9.9 with the wrong carb.<br /><br />If you just HAVE to know, take it to a shop that has a dynamometer. They can tell you the true propshaft hp and the rpm it is reached at.

 

[Dhadley]

Re: How do you verify HP without tearing down engine?

Or throw on a test wheel for a 15. Odds are it wont come up to spec rpm's for a 15 but it will for a 9.9 hp.

 

[gss036]

Re: How do you verify HP without tearing down engine?

That could very well be the reason it will not idle for you as you have posted in this forum. I think it takes more than just a carb change to boost the top end. <br />The old evinrudes would need cylinder head modification to relly get the added horsepower.

 

[Stiletto444]

Re: How do you verify HP without tearing down engine?

The engine is running great. I'm not the one with the idle problem (someone else). I was told the cam for the 15 is slightly different which opens the valves more and allows more fuel into the cylinder. I don't want to pull the cover off and mic the lobes to check though.<br /><br />BTW what is a test wheel? If the weather is good this weekend I'll put it on my boat and check it out. If it performs well then it dosen't matter much.<br /><br />Thanks for the replys,<br />Clay

 

[TOHATSU GURU]

Re: How do you verify HP without tearing down engine?

It's probably a 9.9 that has been bumped up to a 12. That just involves removing the throttle stop screw at the front of the engine.