Good evening, SF.

Last weekend brought some birch trees down, and the task for evenings this week has been to cut up the downed parts.

My pal J brought over his Stihl MS250C and said, "have at it, make sure you know the number for 9-1-1." For the past two evenings, I've come home from work, changed clothes, and cut for a couple of hours. No sweat. Well... there was sweat.

This evening should have been a repeat, but the little Stihl just doesn't want to. This saw has the delayed-start thing, which is a little unnerving. (What's the benefit?)

Got fuel, got choke, got a bunch of yanks on the starter cord... got nothing. I'm in that state of, "well it was running fine when I shut it down yesterday. Why the heck won't it run today?"

Chain saws are like a number of other things in my world -- I can use them, but I don't always know enough to diagnose them when they don't act right. Where do I start?

At this point, it's almost dark and I'm very content with letting it sit 'til morning. But tomorrow morning it had better start -- I've got a lot of work to do!

Thanks, all.

Did the safety brake get tripped?

Could be a flooded carb now if you've attempted a lot of starts with the choke. Pull through it until the engine burps and will fire.

Stihl* starting - Set run switch to choke. Pull until the engine burps once. Move switch to run. Pull once more.

* Regular carb, non Mtronic saws.

On/off switch in the correct position? How much fuel is in the tank? Fill it and see if it starts-might have a broken pickup tube.

quote:

Originally posted by MNSIG:
Did the safety brake get tripped?

Safety brake? Is that the lever ahead of the handle that stops the chain? --> I pulled for a while with that lever both forward and backward. Got nothing but a tired arm in return.

Flooding. Makes sense. Pull through it with the choke still on? Or off? Will it behave differently (better) after I've let it sit overnight? Or does that overdose of fuel stay in the carb?

Remove spark plug and dry it off.

250s can be touchy about flooding. No more than 3 pulls on full choke, then go to half, no matter if the engine burped or not. If it floods, go off choke and give about 20 pulls.

If you pulled a lot with the choke on, it’s flooded. Set the switch to run and be prepared to make many pulls. It should finally fire up. Make sure the switch isn’t set between choke and run. If it is, it will sound distinctly different than when pulling during choke and on run.

quote:

Did the safety brake get tripped?

there is not a single stihl that has this as a starting issue, so exactly what is your point?
Its flooded per your description.

‘His saw’? I’d check the plug, maybe put a new one in.

Sounds like Job One tomorrow is to yank the plug and clean/adjust it.

From what you describe it sounds like it was flooded. I've done that with my MS 250 (also with my MS 291 and old 034). Next day started fine.

Cleaning or replacing the plug is also good idea as has been noted.

Happens to my ms390 all the time.
Remove spark plug. Pull cord 3-4 times. Dry plug.
Reinstall plug.
Do not choke. Put in "high idle"

Pull starter a couple of times. It will then start.

How many hours on the plug? Some 2 strokes can suck the life out of spark plug surprisingly fast. Sometimes it is best just to throw a new plug in with the proper gap and see what happens.

If new plug does not work see if new plug has spark.

quote:

Originally posted by vthoky:
Sounds like Job One tomorrow is to yank the plug and clean/adjust it.

Don't, pull it out and replace it. I had a similar issue with an echo and it turned out the plug was bad.

quote:

Originally posted by ShneaSIG:
250s can be touchy about flooding. No more than 3 pulls on full choke, then go to half, no matter if the engine burped or not. If it floods, go off choke and give about 20 pulls.

I *MUCH* prefer Stihls to Huskies, as it is much easier for me to tell where I am at. It is *almost* always the case that the "burp" is obvious and after pulling the lever up one click to half choke it fires right off. The MS391 threw me a curve today though. Four pulls and not even a hint of a hiccup. None the less, my rule is never more than four on full choke. Switched to half choke, one pull and it was off to the races.

The safety brake (anti-kickback device that locks the chain when forward) won't stop the engine from starting, it will just make it lug a bit once it starts. I normally slap it back to make sure it off before starting "just because" but it isn't necessary. Some folks advocate starting with the safety brake on.

As a rule, I fill the fuel and oil before putting the saw away (we use avgas, so it isn't necessary to drain the fuel), so I always start out with it full. It is worth checking that its full, and make sure that you use mixed fuel.

While at it, check/remove the spark arrestor.

My MS250 is now going on 10 years of hard labor and I concur with the flooding possibility. I have never had a starting issue following the sequence described in the manual, but I have had a "fail to shut off" issue when the kill wire pin vibrated loose. Otherwise, that's one fantastic machine.

Fuel, spark, compression.
Needs all three so start checking there.
The only one you can have too much of is fuel and the spark plug will be wet if that's the case.

Bought a Huskie Electric as a back up this year to my gas powered version. Cuts through decent sized birches like butter. Never thought I'd be that happy with a electric version.