Lawn mowers

Another way of getting one a stubborn small engine to go is to take the filter off the carb, get a propane torch, turn the gas on but don't light it... hold the nozzle to the carb, pull the rope, and the engine will run from the propane torch. Run it long enough to draw the gasoline through the carb 🙂
Some just splashed some methanol over the air filter or down the clean air intake pipe. Only survivable with a cold mower and standing well back. Definitely not recommended.

Just get some sheep or a donkey.
 
When my 25 year old $99 special gas mower deck rotted out I bought an electric mower that was powered by 2 12 volt batteries. The first year I would get about 45 minutes on a charge. Enough to do the fenced in area around the pool and around the trees in our 2 acre property. A lawn tractor did the rest of the yard. The second year the charge only lasted 30 minutes and the 3rd year 15 minutes. A couple of hundred $$ for new batteries and I was good to go again. Three years later same thing. New batteries were needed. I was browsing in the big box stores and saw a gas powered self propelled mower with electric start that was on sale for less than a regular gas mower. I bought it and its so easy to start and use that my wife will cut the lawn maybe once a year now. I have had it for 7 years now. It will probably be my last gas powered one as the local city is planning on banning gas powered lawn equipment for homeowners.
 
Briggs and Statton made so many different motors. Some great, some awful. According to someone I spoke to at B&S years ago, they built engines to a price point. If Sears/Craftsman said they wanted a $15 engine, that's what they got. I owned a generator with a v-twin B&S and it was a fine engine. Some of the go-cart, mower, blower engines - not so great. 😉
 
Seems to me that for that size of lawn cordless electric is the way to go. I have no axe to grind on any particular models but what's not to like?

https://www.amazon.co.uk/dp/B06XWX5...e=osi&th=1&psc=1&ascsubtag=ecSEPgb1sxl0y87h5n

Worst could be that you buy a spare battery, though it's said to be good for up to (we've all heard that before !!) 400m2
Seems none to expensive either. Good luck with your lawn.
As for me, I'm out with the weed killer next week for mine!
 
Seafoam.
I keep wanting a cordless for my small back fenced in "dog yard" but my 30 year old Toro starts first pull. If I were to buy one it would be a Kobalt as I have several 40 and 80V Kobalt tools. Being in NC, I would plug e-go and Green Machines ( they make several brands) as they are local factories.

Just found out the trans lock on my tractor does not go through the ignition switch, so it was left on for a week. Battery dead and shorted so could not be charged. Well, it was 5 years old.
 
I have a snowblower with a Tecumseh engine on it with electric start, now 19 years old it has never failed to start, runs well and the carb was rebuilt about 4 years ago when a belt broke and I decided to get the machine serviced. (I don't think it needed the rebuild) This was probably one of the last engines they built in the U.S. ?
 
For OP I recommend a robot, but I have no experience with them. How do they handle fallen tree cones and branches?

Personally I have 50+ years history with cylinders and B&S engines, also with traction. Nowdays I have three yards to mow. Summer cabin has my old B&S rear wheel drive, parents' house a Stiga Park tractor and at my own house a brand new Makita battery with rear wheel drive and 2x twin 18V batteries (I have many Makita 18V tools). I need traction because we are living on hillside and I'm old... and wife can use it too!

https://www.makitatools.com/products/details/XML08Z
https://www.uittokalusto.fi/stiga-park-220-paketti-b140.html