Okay, so better late than never with my post on my RZT-50 problem. My mower kept dying after about 30 minutes of use but choking it seemed to alleviate it for another half hour or so (with varying degrees of choke). The problem grew progressively worse with shorter time periods of successful operation. I smugly replaced the spark plugs thinking four years without a change had to be it. Nope!
I then realized that the air filter was a little over due for replacement from the last time changed. That didn't solve anything either. I bought a gas filter but when I saw gas in the carburetor and was able to start her up with no problem after a few minutes of cool down time I figured it was a carburetor problem and took the gas filter back without changing it. I'd read that the carburetor solenoid on these puppies frequently goes bad so I had been trying to find a way to remove it to try the temporary bolt fill-in test method. Unfortunately I wasn't able to find a tool to fit into the tight space to remove the solenoid (most ignition wrench sets did not go up to the 1/2" I measured that was needed and I wasn't about to pay what most places wanted for a special order). By the way, I received a new BBQ grill for father's day which came with... you guessed it... one of those cheap little wrenches that happened to be the right size.
Anyway, my last ditch effort at diagnosis was to buy an inline spark tester. I was getting desperate as my backup mowers can barely handle the load. I decided that if the spark tester did not indicate a problem then I would bite the bullet and take the mower in for repair (something I have only done twice in my 56 years on this planet). Before I tried the spark tester I bought another gas filter to try a quick and easy solution (even though previous diagnosis indicated otherwise) and I'll be damned if that wasn't the problem all along! I've never ever had to change a gas filter in a riding mower before (not even in a Murray that I owned for 10 years).
Anyway, this mower has been a champ for me since the day I bought it. I have not experienced the hydraulic issues that many owners have had and the majority of the problems I have had have been self inflicted. I, for one, recommend the Cub Cadet RZT-50 to anyone looking for a low cost zero turn of this size.