I am in the process of cahnging all my vehicles, lawn mowers, etc over to diesel, WVO, WMO, etc. I have an Airens ZTR mower with a gas engine. I would like to find a diesel engine replacement for it. Does anybody know if they have NEMA-like standards for gas or diesel engines like they have for electric motors? Then the mounting holes and shaft sizes would match up to minimize the finaggling to get this to work.