Hello folks: Just bought my first Yanmar 4x4 tractor with loader. I've searched extensively to make sense of the model and serial number plates, and could use some help ! This is a 226D tractor, fender plate reads YM220-226 The engraving on the left side of the transmission case although badly rusted) looks to read 226D-11653. I'm trying to figure the year of this tractor and possibly obtain a parts manual for it. I've only narrowed the year from 1981 to 1991 ???? Everything seems to work well, hydraulics are noisy and slow when first started in the cold but seem fine after warming up. Any thoughts on issues I should be watching for Thanks