i just got an hour meter/tachometer. My 12.5 hp toro 36 runs no load at about 3400-3500, with my double blades on each spindle, it runs about 3200 (i haven't cut grass with tha tach, this was on my drive way). i think i need to tighten my belts, but that shouldn't affect RPMs that much. what should i be running at no load and loaded? how do I adjust the governor? Shouldn't the engine run at 3600 RPM, if i hold the throttle open manually, it will run 3600, evnen with double blades, i don't want that reserve power to go unused<p>my 5.5 hp 21 inch JD walk behind runs no load at 2800, when i took the carb off to clean it this winter, i didn't put the choke linkage back on, any tips on how to put that on? oh and when i engage the blades, it just stalls, i have to let it warm up thoroughly, its like the governor isn't giving it any more gas. what RPM should this engine run at, isn't it different because of OSHA blade tip speed requirements?