re-power motor selection.... Old vs new ratings, how to tell if you have enough....

daryng

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  • / re-power motor selection.... Old vs new ratings, how to tell if you have enough....
Hello,

I'm new to the forum but have used it as a resource for several years. I'm looking to repower a zero turn that had a 29hp rated Kawasaki. This mower was a 2009 model year, so my question is. Is this number inflated? According to small engine warehouse, the actual net HP should be about 25.5hp. I'm looking to replace with a Honda GXV690 which under the current ratings is 22.8hp. I have found some listings of this honda engine as it formerly being rated at 28hp but I can't verify this. I guess its just the question of who exaggerated the most with the old ratings Kawasaki, or Honda, or If I go by the new HP rating system, will I be missing the extra 2.7hp that I gave up by going with the Honda. I already have the motor (honda, which was purchased a while ago for another project) and I'm just wondering if I'm going to be lacking in power? the displacement between the two engine is quite different. Kawasaki at 852cc and Honda at 688cc. as well as the torque ratings. I know the saying "no replacement for ......." but I believe with newer technology that may not be true anymore i.e. modern GM 6.0L V8 will out perform an older GM 7.4L....

Yes, I am aware not all engines are created equally and aren't drop in replacements. I am crafty and come from a family with a rich tradition in "engineering" things to work. Not to mention a personal machine shop....

This motor will be driving a 60" deck, often times in thick green Missouri fescue. Any suggestions would be appreciated.
 

ILENGINE

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  • / re-power motor selection.... Old vs new ratings, how to tell if you have enough....
I think you will miss the extra power. I try to compare displacements and torque ratings more than HP. Even with the same torque ratings extra displacement can help power through tough spots.
 
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