You are putting an unusual amount of hours on that engine. Are you a commercial operator?
Remember that the engine is working under severe conditions. Full throttle under load, hot weather and a dusty environment all play havoc on what by automotive standards is a crude unit. Don't skimp on maintenance.

You think you have to change it too frequently, but don't want to leave 4 oz. of old oil, so you pay for a new filter?

It seems to me that you should change the oil at the 1st 50 hrs and then every 200hrs therafter not necessarily change it. Either that or Briggs is making cheap engines these days. My beast of a mower is every 200 hrs (see pic below) and it dont necessarily need a change then. only if i have been running it at full throttle which i rarely do. and this schedule is true for all Kubota mowers gas and diesel alike.

Here is a link that might be useful: Kubota maintenence schedule

Are the Kubota's AIR COOLED?

Oil changes are for us that expect or equipment to last 10 to 20 years or beyond without oil related failure. Those of you that run your machines couple of years and get new ones are usually the ones that skimp on pre-ventive maintenance form pass experience that there not going to last so you buy new one before failure. Skimp on oil changes on air cooled engine and they will mostly go bang after all the symtoms like smoking, knocking and using oil from lack of maintenance after few years of use. I would skimp on anything else but not OIL Changes.!!

The key difference in the requirements of air cooled engine versus liquid cooled engine regarding oil useful life span is due to the normal operating temperatures in the 2 types of engines.
Properly maintained liquid cooled engines will operate at temperatures ranging from about 180 F to 192 F, and that temperature will be almost uniformly constant at all points throughout the engine.
Air cooled engines in contrast have a normal operating temperature that is quite hotter overall, varies a lot depending on ambient air temperature/engine loading, and.........have locally isolated "hot spots" that get much hotter than other places on the engine.
Liquid cooled engines, by design, have few places where the oil actually comes into contact with extremely hot components (the underside surfaces of the piston for example).
Air cooled engines expose their oil to ALL of the extremely hot components intentionally because in these engine, the oil is used not just for slickum, but as a coolant too.
By virtue of the oil absorbing/collecting heat from the hottest spots..........and then losing some heat when the oil is distributed onto cooler components during its circulation, the average engine temperature is a little bit evened out............but never to the degree of a liquid cooled engine.
Bottom line is this: The extreme conditions that assault the oil in an air cooled engine might be 4 times more severe than what it would face if used in a liquid cooled engine (based on a presumed arbitrary rate of heat degradation effect on the oil). So it would seem (to me) that air cooled engine oil would have a life span only 1/4 of that for a liquid cooled engine, hence the 4X more often oil change interval.

In this case, water cooled vs air cooled = apples and oranges.

I say again, many lawn tractors that die a premature death were murdered.

I have a Murrey with a 12HP Briggs motor that I bought in the late 80's. It doesn't have an hour meter or filter. It is still kicking and doesn't use any oil.

I changed it twice a year. Mid summer and when I was through in the fall. I probably only put about 150 hours a year on it. That is why I'm thinking every 50 hours is excessive.

I still use it for mulching and sucking up leaves with my leaf vac. I guess they made better motors then? ;)

"You are putting an unusual amount of hours on that engine. Are you a commercial operator?"

Nope, I just have a lot of acreage to cut! About 4 acres in the front yards plenty more in the back yards and lots of obstacles. Two houses that sit way back from the road. I need to plow it under and plant corn!

I'll keep changing it at 50 hours, maybe skip the oil filter on every change, it will be a hard habit to break.

Thanks to all.

When you consider that the same filter can be used on a 4.7L Lexus, it should be adequate .5L engine.

I didnt think about that too many beers during that post its liquid cooled so i didnt think about that till now i guess liguid would keep the oil much cooler when running my fault.

Not a problem KM, have another sudsy. :^)