Frankman, I have a 1996 Kubota T1760 with a kawasaki twin cylinder liquid cooled engine as well. I think mine is only a 17hp but may be an 18. For almost 5 years now, I have been dealing with fuel starvation problems. Engine just dies while I'm mowing.Will only run sometimes in choke. Four years ago, I took the carb off and cleaned it and noticed rust colored sludge in the bottom of the float bowl. Cleaned that out and the tractor ran fine for about a year. Next spring, engine stopped when mowing. Only would run in choke position. Over the next two years, it would run OK for 2 hours and then would ide. I'd wait until the next day to start and things would be ok.
This spring 2012, it stopped while mowing and after talking to my local useless, tight lipped Kubota dealer, decided to remove carb and clean with carb cleaner and compressed air. I took the governor arm off and has proved to be very touchy to get the right position back. Once I got it going again the mower slowed down under a load, moderate mowing. Took the carb off again an let my dealer hot ultrasonically clean it. 45.00!! His suggestion. Brought it home and it ran pretty good for about 1/2 hour when engine died. I drained the carb bowl and found black specks and scale in the gasoline. Figured the fuel hose downstream from the filter were deteriorating. (Read article on the internet about ethanol ruining fuel lines.) Decided to replace fuel line to fuel pump and from pump to carb. I checked the fuel coming out of the filter thru new hose. Clean. Hooked it up to the fuel pump and turned the engine over to check the output of the fuel pump before connecting FP to carb. My container filled with gasoline, but also many black particles and scale. I did this four times and the last time banged on the fuel pump with the handle end of a scewdriver. Larger particles pumped out, most as big as the head of a pin. Let them dry and discovered they were rust particles. The only culprit could be the fuel pump housing which is made of steel. I'm about to order a new one, but I'm quite sure it is the root of my problem all these years. Long story but hope this helps. P.S. this fuel pumped is over 16 years old.