Couple of things I've come across with these engines -
1. Inspect, clean or replace the air filter often. From what I have seen, they plug up very quickly. They are a very basic paper cartridge which I believe can't be cleaned out like the older oiled foam filters. They aren't all that expensive, so I keep a couple of hand to swap as needed. I also recommend having the foam pre-filter sock, which can be cleaned and extends the life of the paper cartridge. And finally, make sure to buy genuine here, the last thing you want is a cheap Amazon filter not sealing properly and dusting the engine.
P/N - 593260 (filter) & 798452 (pre-filter)
This oval style, pleated-paper air filter provides superior protection against the destructive effects of dirt ingestion. Used on 550e-550ex Series engines, this OEM part ensure proper fit and performance to maintain the life of your Briggs and Stratton engine. Oval style, pleated paper air...
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2. Stick with the mineral SAE30 oil for the first 15 - 20 hours, then swap to 10W-30 synthetic/semi-synthetic from then onwards. The old mono-grade stuff is good for running in, but is not really needed on the new OHV engines. Briggs always specified SAE30 to account for the loose tolerances on their older flat-head engines.
3. Oil capacity is 440ml or 15-oz. Considering the whole no oil change thing, that oil capacity is
less than the older side-vales, which was 600ml / 20-oz. That means you have less leeway, most mower owners would never check the oil, let alone top it up or actually change it.
4. Spark plug is Champion RC12YC or NGK BCPR5ES, gapped to 0.76mm.
5. You can bump the top speed of the engine to improve performance. I've done this on all of my 4-strokes, mainly because the factory setting is just too low, usually about 2800 - 2900 rpm. I aim for 3600 - 3800 rpm, which is where older mower engines used to sit. The only reason why they do this is to limit exhaust and noise emissions.
To adjust the governor on the new OHV engines, there is a bendable tab just behind the air filter housing. The following video shows how to do it, even though it shows the smaller 125cc version, the adjustments are the same. If you don't have a tacho, just be careful not to go too far, you will hear what sounds about right.
Mine after a little "tune up", as you can hear, it makes the engine sound like its actually doing something..............................................