I have a 30" push Craftsman mower. I stopped using it because I needed to hire a landscaper to mow. It's been left outside for 3 years and definitely won't start. I am thinking of starting to do the mowing myself and the question is is it worth it to get this repaired. I spent $1,000 when I bought it and I don't have the expertise to repair it myself. Talked to a local repair shop who said repairs could be north of $500 but I need to have them look at it. I'm ok if it's not worth it, might make more sense to buy a new mower. Thanks for all your thoughts.
Buy a new spark plug, drain and fill the fuel tank with new premium gas, drain the carburetor of built up moisture, pull the starter cord with the choke on while the plug is out, this will get some fresh fuel through it faster, let it evaporate for a day before putting the new plug in. You can also connect the new plug before installing it and crank the engine while the plug is grounded against the engine, see if you get a good spark. Of course if you find that it does work, change the crankcase oil and air filter.
All an engine needs is air, fuel, and spark. If you don't have the expertise to repair it and don't want to spend big money to have it done, then your best bet would be buy a new one. Maybe you could find a deal on a used mower in your area. The only thing is, whether you pay to repair it or replace it, it would be a shame to spend the money only to decide for some reason you didn't or couldn't mow yourself.
My best guess if the mower was working before it sat, and it was stored with fuel in it, probably the old fuel needs to be flushed out and the carb get a good cleaning. Also check for rodent damage to wires. Repair shops can quote all kinds of numbers but it might be worth having them just concentrate on the fuel system. If that doesn't do it I'd move on.
These small engines are pretty simple. An old saying is if it is has compression, is getting fuel/air mixture, and has a spark, it has to start - it has no choice!
Clean or replace the plug and check for spark. Clean or replace the air filter.
Much of the time the problem with one that has been sitting around is the carburetor. I've repaired many by simply disassembling, cleaning, and reinstalling the carb. Sometimes a carb rebuild kit makes this easier.
If gas was left it for three years check the main jet. A generator I left setting wouldn't start even though everything looked good. I could see light through the jet so it wasn't stopped up. However, it turned out some varnish had built up evenly on the inside of the jet, reducing the ID and choking off the gas supply. Cleaning that with the right size fine wire (I used a tiny precision drill bit, turned by fingers) and it started right up.
If you're not comfortable with doing any of this you may have an friend or neighbor who might offer to do it. I've worked on many engines for others.
To prevent aging gas in the systems, At the end of each season mowing or snow throwing, I routinely run either machine of that season until it runs out of fuel. They only have trace amount of fuel. But then I have to push it into the garage.
I also have a small engine repair place nearby that has a trailer and they will pick-up /deliver my lawn tractor and snow thrower. They do both machines at the same time machines get new plugs, filters, oil, grease and tune up including sharpening grass cutting blade.
A small engine repair business in the area has explained more than once that many carboreteurs still have fuel in them when the engine "runs out of gas" and the remaining gas will absorb moisture and lead to carb problems. His avvice is to start every engine once a month when it is not being regularly used, and let it run long enough for any water in the carb to be drawn into the combustion chamber.
I wonder how many people actually start a lawn mower or snow thrower ONCE A MONTH all year long. I wouldn't remember to do that. IN any event, running the tank dry at least means there is little if any old gas in the tank. Every other year I send it to the small engine shop for a tune-up. I haven't had any problem with the carb. My lawn tractor is more than 25 years old. The snow thrower is more like 15 to 20 years old.