I currently own a Massey 1652 HST cab. That's an Iseki 3.0L 4cyl (55hp) diesel. ((Previously i owned: Massey 1648 with Iseki 2.2L 4cyl (48hp); LS R4041 & R4047 with LS built Mitsubishi 2.2L 4cyl engines; Kioti CK20 with Kioti 0.9L 3cyl (21hp).
I also currently have a Terex/ASV track loader with Cat-Perkins 3.3L 4cyl (80hp) which is actually a Mitsubishi engine.
I also currently have a Hustler Super-Z Diesel commercial mower, with a Shibaura 1.7L 3cyl (25hp).
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I will say that my Cat-Perkins Mitsubishi in my Terex is the best winter starter of the bunch. It starts smooth even in the winter. The next best were the LS built Mitsubishi engines. Then, i would say that my Iseki, Shibaura, and Kioti diesels all share the bottom spots in my fleet for winter starting.
Can't complain about any of them regarding performance, they've all performed as expected. The Iseki Tier3 engines are good, old tech engines.
I don't think you'll go wrong with either.