You hit a sore spot with this thread. I moved to Northern Florida in 2017, a hurricane hit about two weeks later, and I have been fighting with chainsaws ever since. I received tons of terrible advice, and some came from pros. I suffered a lot and wasted a lot of money. I finally got some good information, which I will pass on.
I have an ECHO CS-590, and I thought it was a piece of junk until I got this information. You have to know what you're doing to make this saw work, but once you know, it's a great saw and a real bargain. It has a metal case, which is unusual in a Home-Depot-grade saw.
First off, when you are not using your saw, fill the carb with motor oil. This is the secret no one seems to know. Modern gas is garbage even when it has no ethanol in it. It will clog your saw and harden the diaphragm. Oil will prevent this. Running it dry probably will not work. I have run saws dry and had them clog anyway. I'm talking about saws that may sit for months, not saws that sit for two weeks. It's not the same.
Second, use ethanol-free gas because, while it's still bad, it's much better than ethanol gas. Any gas you buy at the pump can turn into varnish, but adding alcohol and water makes things worse.
Third, when you get your gas and mix and treat it, use a Sharpie to put the date on the gas can. When you're two months past the date, pour the gas out and get new gas.
Fourth, if you can't drain your saw, use Biobor EB to treat your gas. Do not use Sta-bil red, which only works for equipment that never moves. Biobor EB will extend the time it takes gas to ruin your carburetor.
Fifth, don't listen to idiots when they tell you how to start a saw. Here's what to do:
A. Make very sure your ignition is on before you try to start the saw. In fact, leave it on all the time, because if you don't, you will forget to turn it on, and you will flood the saw. Use the choke to stop the saw. You don't need to shut off the ignition.
B. Pump the daylights out of the purge valve. It's not a primer bulb. It pushes fuel through the carb to get the air out. You can't pump it too much. You will not flood the saw.
C. Pull the choke out even if the saw is warm. If it's warm, push it back in before starting. Pulling the choke out will open the throttle and keep it open so the saw gets gas while you're trying to start it. The throttle will stay open until you pull the trigger.
D. Use the compression release if you have one. It will not prevent the saw from starting, no matter what anyone says.
E. Pull the cord out a couple of inches and then yank as hard as possible to start the saw.
F. Release the brake immediately when the saw starts (so you don't fry it while the saw is revving) and goose the throttle to warm up the saw.
If your saw won't start, the first move is to dump the fuel and start over. If the fuel isn't the problem, the carb is probably clogged.
If you flood the saw, try starting it with the throttle fully engaged.
Heat ruins saws, so keep your chains sharp. A dull saw makes the engine work hard, so the saw gets hotter. A sharp saw makes flakes, not dust. Get a Pferd sharpener. You don't need anything fancy. Takes, literally, 5 minutes to sharpen a saw. Do it once per tank. Make sure you file the rakers when needed.
Consider modifying your exhaust. Some saws have restrictive exhausts.
If your bar has a lube port, use it. Buy a chainsaw grease gun.
If you have a CS-590, change the timing, because it's set wrong at the factory. You can buy and install a part (timing key) for this. You can also put an exhaust deflector on it to open things up and reduce heat. I got great results this way.
You can get a carb for a bigger Echo and install it. A cheap tach will let you tune the carb. Remove the limiter caps from your carb once you know what you're doing. They're there to keep noobs from burning up saws, but you can greatly exceed the factory RPM limit and get better performance if you tune your saw.
Echo doesn't warranty carbs, by the way. This is because carbs are what usually need to be fixed.
You can rebuild an Echo (Walbro) carb in a few minutes with simple tools. This is less aggravation than taking it to a mechanic or cleaning it. Most mechanics are incompetent, and they charge $100 per hour or more. Get a real Echo kit.
I bought an expensive Husqvarna pro saw (562XP) because pro saws start more reliably, and the Echo seems to pull just as well now. Before I fixed the Echo and learned how to use it correctly, it sat in my shop for very long periods because I could not make it run.
Pro saws have electronics in them to make the run better, so this is part of what you pay for when you buy one, in addition to a tougher case and so on. The Husky has this stuff. The Echo does not.
You can also install a different main jet. The one that comes with the Echo has an unnecessary hole in it.
My Echo made me miserable for several years, but now that it's working, I really like it. Because it's made for homeowners, it comes with "features" that cause problems but protect the saw. Once they're gone, it's great.
Best tip of all: do not buy a gas saw unless you really need it. I have a Makita with two 5-Ah batteries, and it will handle 9/10 of the jobs I need a saw for. It always starts. It cuts like crazy. No ear protection. Makita designed it to be easy to use. If you get one of these and 4 batteries, you may never need a gas saw unless you're cutting firewood.
Also, get a battery pole saw. It will handle most jobs a homeowner has to do, and it will keep you away from the cut so you are less likely to drop a branch on your head or be killed by a barber chair. I bought a $99 Kobalt that looks like a toy, and it has been incredible. I also have a gas pole saw, a corded pole saw, and a much sturdier Ego pole saw, so I'm not blowing smoke here.
You can use a pole saw on a ladder, and you can also use it to make cuts above shoulder level. With a chainsaw, those are both activities that land people on operating tables.
Another great tip: get a hard hat with a mesh shield and muffs built in. Amazon sells one made by Oregon, and it's only $40. It's great.
Finally, don't use canned fuel. Some people swear by it, but others have had a lot of problems with it.
I learned all this stuff from years of suffering. Listen to me, or repeat my mistakes.
Oh...also, if you're cutting anything big get a Timberjack. Big help.
