I retired about 3 years ago after 48 years as a Ford/Lincoln Mercury tech. Now I spend my time fixing other things. I have a neighbor with a 1999 Exmark Lazer Z, model LZ22LKA604 and serial #204513 and engine #FD661D003939. It is a Kawasaki V twin, water cooled. Over the years I have replaced the gaskets in the right hydro pump, and replaced the spindles, and welded patches on the deck.
Now it runs fine, but the engine overheats. Cooling radiator is clean and the fan runs. The air coming from the radiator and the radiator itself are cold. I believe I have a thermostat or water pump problem.
In the pictures I have seen, the water pump appears to be gear driven. Are there any special procedures for replacing this pump?
I would appreciate any information you could give me. Thank you for your time.
I'm not familiar with that particular engine but the FD620's used plastic water pump gears which often failed. Impeller not spin, it don't circulate water, and don't cool very well.
also had a number of them with broken cam gears too...and broken rivets that hold the plastic cam gear to the cam itself. Have bought a bunch of 425 and 445 deere's with that issue (no compression), replace cam and gear and water pump, and send it. The engine itself outside the plastic gears, is very reliable and very forgiving.
