just picked up a 612 grasshopper cheap, was planning on using on smaller residential yards instead of using the 60 inch for the smaller yards, anyways i know the 12.5 is alittle underpowered, but it works for smaller residential yards. also i dont have a manual for it 1) what type of hydro fluid should go in those? 2) is it possible to switch from single tail wheel to dual wheel? think thats the wide stance? 3) mower is in excellent shape would repowering it to a new 16 hp be worth it? I saw them online for around 775.00 for the new motor, is it going to be a noticeable difference? the 12.5hp runs fine maybe i could sell it to help pay towards a new 16 hp i will say its not nearly as fast as my ferris but it beats the hell out of a belt driven walk behind!