OK, I don't own a B3350, but tractor data shows ... "The B3350SU Special Utility was a low-cost version of the B3350. It did not have a mid PTO and the hydraulics did not have position control"...., so I assume it has to be very,very similar to the B3350HSDC which kubotabooks does have the WSM posted. I downloaded it, and the electrical section does have the schematic.
There is no connector or mention of that emulator,and a quik scan of the pictures in the engine section don't show the small 'black box' on the engine.
I understand what's inside the Turkish made device(rather simple electronics to me.) and there's no way it left the Kubota factory with it installed. Logically,rationally it doesn't make sense that Kubota would install a foreign made after market device at the factory. Pretty sure they'd have stuff designed,built,tested in Japan,under their control. It'd be interesting to hear from every other B3350Su owner if they have the 'black box' on their engine.Now if the emulator company(sail ??? )would open their books up and search sales records for 2014 (?), it'd be interesting to see who in the USA bought the emulator.It would take less than a minute to see who did.
I am NOT calling you a liar, but I suspect someone, maybe the dealer ?, installed it ,before you bought the tractor knowing that series had 'issues', similar to the VW scandal few years ago.