I currenly have a 91 Vanguard with the Briggs 16 hp opposed engine. I also have just come into possession of a 18 hp Kohler CH18S. What are the thoughts on an engine swap. I would have to find a clutch as the Briggs is a screw on style. Would the difference in hp be worth the hassle and expense? I would like a bit more power or should I maybe hold out for an engine of the 20 to 25 hp range. I have a set of super tracks that really taxes the engine. I also wonder if too many ponies in that machine would tear every thing apart. I am not in a financial position to throw away good money after bad, if you know what I am saying. Finding used parts in my area, like a clutch could be next to impossible. Are there still people looking for opposed twins for their machines? Lot's of questions. This site is excellent for opinion and advice. I do have the tools, knowledge, and area to perform a transplant. The machine is used for hunting in the fall and winter as there are no places to just ride it anymore.