I ran a little Auto-Rx in my 6 horsepower briggs engine for about 2 months, went out today and started it too run the gas out, changed oil after running it for 10 minutes, it came out a little dark, added new oil and ran out the gas, should I run a rinse phase like we do for our car engines.
I have an Ariens riding lawnmower with 11.HP Briggs&Stratton engine at the time it was using 3oz of oil every 3 hours of running time. since it holds 1 quart of oil I use 2oz of ARX. and run it 8 to 10 hours dump the oil put in new no rinse phase is necessary you can use the same application fo a 6Hp engine I have done quite a few tests with a lawnmower and Frank has given instructions for my engine also it stopped burning oil.
I've also experienced less oil consumption after ARXing a 3~ HP B&S engine. I like to keep a very small maintenance dose of ARX in it at all times. I generally change the oil once or twice a season. That's probably overkill but cheap insurance since there is no oil filter.
I changed the oil on my other mower that has a Kawasaki engine, and it has an oil filter, it also had Auto-Rx in there and when I changed the oil it was darker than the previous time and the filter was heavier than the previous time, proof that Auto-Rx works in small engines, will be running Auto-Rx in my snowblower too when I change the oil.