MS361 No run

Ran perfectly the last couple days. Went out to cut more rounds, and nothing. Put a new spark plug in, cleaned the air filter. Tank filter looks good. Won't fire. Just fuel out the exhaust after trying to start it & plug flooded with fuel also. Any ideas?

Do you have spark?

+1 - check for spark first. Cheers!

Didn't see any spark. Took carb off and sprayed it down with starting fluid to clean it off. put back together, it tried, then nothing. So I became persistent pulling, and she started trying more and more, till she finally started, and seamed to clear out. Not sure, but ran great all day after that.

I'm not sure exactly how you checked without more detail, but if it truely "had no spark" at one point than a good first place to start investigating is the ignition system. You changed out the plug, so that is good, so I'd investigate the plug wire, ignition module, and gap setting for possible problems.

I have an 026 that was giving me intermittent trouble and it turned out to be a tiny burned hole through the plug wire under the cover where it was making contact with metal on an anitvibration mount occasionally, arching out and killing it.

Also have an 031 that was so packed with crud under the gas tank/flywheel cover that the entire gap to the flywheel was filled solid. Cleaned that all up and re-set the gap (usually .008-.012, I set them to .010 with feelers versus the old "business card" guess) and it ran smooth again.

As long as it keeps running fine I'd just run it................ but if it acts up again with "no spark" start looking here for something!

Howgildz, I see that you live next to a Nuke Plant .............. I can relate to that ............... I visited Chernobyl in 1992.

I'm thinkin' I might need to do another video -"How to clear a flooded saw."

Hogz - Glad you got'er rollin' again.

Hogwildz, did you have this problem on a cold start or only when attempting to start after running it for a while?

The several Stihl saws I have or have used are real picky about how to start them so they don't flood. Now that I have a "system" it's not too bad, but before that I about threw the damn things in the woods and left!

I use to do that on a 361 quite offten. Its hard for me to hear that first pop. You miss it and its over!

My 270 is very temperamental. I have come to pull it two or three times on full choke, then to half. If I try to pull until it fires, nine times out of ten it doesn't, it just floods.

My 361 has a specific routine...and if you don't follow it there's a good chance you will flood it.

Stone cold: full choke 3 or 4 pulls till it pops, then fast idle 2 pulls.

Hot: just in the "on" position, one pull.

Medium (been run recently)?: This is where it gets dicey...start with "on" position...if it doesn't fire in 2 pulls, treat it like its cold. Never start out like it is cold..that's where you flood it.

MM - I would like the "un-flood" video. I have not flooded a saw - YET - but I have other things and love the visual help. My Husky is cold blooded on a cold start. Has been since new and I have read this is common with this particular saw. I wish it wasn't so but I have come to understand it and just have to pull, alot, to get it going for the first cut of the day.

I haven't figured out a good way to un-flood a Stihl. On other engines you can open the choke and set to WOT and pull a LOT. That will *sometimes* flow enough air through the engine to dry out the cylinder. Doesn't work on a Stihl (or you'd have to hold the trigger with one hand) since WOT lock is also full choke.

This method probably only works 50/50, if that. Best method is to go drink a beer and let it dry out naturally.

OR invest in a seven saw plan...

I unflood my 361 by putting it in the run (not choke, not fast idle, not with throttle depressed) position and pulling a 5-10 times until it pops. Works for me.

One other issue with my 361 is that the fuel tank breather valve doesn't work very well and sometimes causes a vapor lock. If you crack open the fuel cap immediately after shutting it off, you will relieve the low pressure condition and eliminate the difficulty when you go to start it again. You'll know if this is your issue when you run the saw for a good while and you hear a strong sucking sound when you loosen the fuel cap.

I'm betting you flooded the saw, Hogz, and once you do that you will not see spark on the plug when you test it (if you do see spark, it'll be weak). I've found if I flood a saw, I'll pull the plug out of the saw, pull the start cord several times to help clear out the gas a little, and stand the saw in a position that allows the gas mix to drain out of the spark plug hole. Let it like that for several minutes til' the crankcase is completely empty. If you try and swap plugs with a loaded crankcase, it'll likely foul your new plug right away.....

Also, I've used a propane torch to 'burn off' the electrode after fouling many times. Just a couple 'redneck' pointers for you. Glad you got it running again..

I had the vent replaced and it still occurs. It doesn't happen all the time. It's usually after using more than half a tank on a hot day.

YIKES!!

Maybe I've had two bad/clogged breather valves! (Wouldn't be surprised.) The good thing is I haven't had a vapor lock in a very long time, and it's mainly because my SOP is to open the fuel cap for an instant after I've been running the saw for a long time. I still hear that sucking sound sometimes.

I use 93 octane gas from a supposedly reputable station and Stihl Ultra at 50:1 and keep it fresh. This summer I'll try a different gas station and see what happens.

From you, absolutely not!!