The chainsaw is used I assume. Can you check the compression? Air filter clean? You should get at least a pop if you are dumping fuel directly into the cylinder and you have spark and good compression.

Well I don't have anything to check the compression.Unless you can tell how to.
Jack

Checking compression is pretty simple. But you do need a compression tester :). You can get them for ~$20, make sure the tester has a check valve at the point it screws into the cylinder. Saws have such small displacement that the airspace in the tube will affect your numbers. A check valve at the base will have you measuring the cylinder compression. Simply remove the spark plug, screw in the tester and pull the starter rope a few times. I think you'll want to figure out how far you want to go with this saw and what tools you'd be willing to buy. I think the 180's go for ~$230 new. Factor that and your time into whether you want to try to repair.

A paste of some other info I just read regarding a non-starting saw. This was a question about an Stihl 026 not starting but most applies to your symptoms.

"Do you have spark?
Do you have compression?

If yes on both then try a splash of mixed gas down the carb and see if it fires, if it does, then you likely have a fuel problem, check the pulse line, fuel line and then carb.

If you have spark and compression and it still won't fire even with gas dumped in, then the other possibility is a fly wheel that has spun on the shaft.

There is no carb bowl to speek of, sometimes passages can be plugged, fuel pump valves pooped or the needle stuck. Often the fuel lines or pulse lines rot and that will give a no start.

No spark, check the on off switch and plug then good chance it's a bad coil coil or coil wire."

If your compression is bad, I don't think this saw would be worth repairing. It could be as cheap as your rings, moving up the chain gets you to your piston, after that your cylinder.

If you dump fuel down the plug hole put it in the run position and hold the throttle wide open, you might have it flooded real bad. Is the plug sopping wet after you try to start it, if it's really flooded it might take up to 20 pulls with the throttle wide open. Also try another plug. Steve

The plug has very little fuel on it.

The flywheel is off.The key looks like it is part of the flywheel.Is this the way Stihl makes their saws?
Jack

Yes thats how the key is made with about 5 degrees of slop, try and get it kind of centered when putting it back toegther. With a dry plug try giving it a bigger dose of mix down the plug hole, it should run a couple of seconds doing that. I'd guess your carb is clogged, gas doesn't keep very long anymore. Steve

"you might have it flooded real bad" and that's why I use carb cleaner for priming. It's hard to flood the the engine. the raw gas gets down into the crankcase and still floods the engine for awhile especially if you see gas running out the muffler. It's takes alot of carb. cleaner to cause that, but IMO very little gas due to IMO you can't control the exact amount of gas going into the engine unless you have a measuring device.

Here's what I would do. Remove the spark plug, plug it back in, ground it against the head or metal part of the engine. With the switch on, Pull the rope, do you see spark. If that answer is yes, then spray some carb cleaner into the spark plug hole. pull the rope a couple of times to blow out any excess (this primes the cylinder for starting) Now clean the plug and check the gap. should be .017 thousands or so (or what ever sthil recommends). now spray the spark plug with carb cleaner for priming, (why cause most of the carb cleaner fluid you sprayed into the combustion chamber has already evaporated). Install the plug holding the throttle wide open with the switch on. pull the rope should fire on the second or third pull. If you get a pop, spray some carb cleaner down the carb (a two or three second blast is all it takes). Again hold the throttle wide open and pull the rope. it should at least start and rev up enough to burn the carb cleaner you sprayed in. If so now you got the get gas to flow from the tank through the carb. usually if you repeat the priming process (spraying the carb. cleaner down the carb. three or four times the engine will usually suck the gas up from the tank and through the carb or just push the primer buttom till you see a steady stream of gas flowing into and out of the carb. You said you replaced the coil I would also check the gap between the coil and the flywheel, maybe if off??

The first thing I would do is remove the muffler and take a peek at the piston through the exhaust ports. A light scratch or two won't hurt anything but deep scratches or galling means she's D.O.A and not worth spending any more time on. Do a systematic check before you start throwing expensive parts like a coil at it.

Thanks for all the help.I pick the saw up by the pull cord.The saw stayed on the ground.I have a bad scared piston.
Jack

Ok unless you done what Canguy said or had the spark plug removed where their was no compression IMO that's the only way to tell if you have gulled/scored from not enough oil in gas cylinder wall and pistion other than removing the jug.

I did do what Canguy said.I found the piston scared very bad.