New to the MM game, been lurking around on here and learning a lot. Question is I need performance parts for a 21 hp Kohler. Any help is greatly appreciated. Thanks

In my opinion, and you'll hear alot of them here, most people don't work on the smaller HP motors cause its cheaper in the long run to buy a higher horsepower engine.

I mean you have a 21hp and instead of spending $1000 in parts to make it a 25hp, just trade up to a 25hp. http://cgi.ebay.com/Kohler-V-Twin-25-HP ... 588aa4130c

Or 1900 for a 35.
http://cgi.ebay.com/35hp-Briggs-Stratto ... 1e5f50faa3

Most guys are working on their 35's cause that's the biggest motor made and to get more out of it you have to use performance parts.

So my advice to you would be to buy a larger motor and pop it on your current frame.

x2