What are the signs of overheating & scoring?

[Canyon Angler]

I was ripping some nasty unsplittable year-old sweet gum, and it was a fairly warm day (maybe 65°) so I was allowing the saw to idle a minute or two to cool off between ripping 8" diameter rounds. Suddenly my almost new 361 started blubbering and shaking when I went to open the throttle, almost as if it was too rich, or it had "jumped time" or like it was out of balance (like a washing machine drum when it shakes)...what could cause this?

I tried to juice the throttle with no load and it did the same thing, almost like it didn't want to run. I wanted to let it idle to cool down with the help of the fan, but I was more afraid of doing more damage by allowing it to run, so I shut it down to cool.

Can anyone give me a clue as to why this might happen, and what to do to diagnose it and prevent it in the future?

Should I pull my muffler and check for scoring?

Oh please, oh please, I hope my 361 isn't damaged!

 

[04ultra]

I was ripping some nasty unsplittable year-old sweet gum, and it was a fairly warm day (maybe 65°) so I was allowing the saw to idle a minute or two to cool off between ripping 8" diameter rounds. Suddenly my almost new 361 started blubbering and shaking when I went to open the throttle, almost as if it was too rich, or it had "jumped time" or like it was out of balance (like a washing machine drum when it shakes)...what could cause this?

I tried to juice the throttle with no load and it did the same thing, almost like it didn't want to run. I wanted to let it idle to cool down with the help of the fan, but I was more afraid of doing more damage by allowing it to run, so I shut it down to cool.

Can anyone give me a clue as to why this might happen, and what to do to diagnose it and prevent it in the future?

Should I pull my muffler and check for scoring?

Oh please, oh please, I hope my 361 isn't damaged!

Pull the muffler and look at the piston..It wouldn't hurt..

.

 

[blis]

If the saw overheats it generally looses idle or it becomes really unstable, but it should still run fine when giving some throttle...

My best quess is that your stihl decided to commit suicide since it didnt like its life...

Seriously, bearing failure or something similar or something dodgy with your mix...

 

[Canyon Angler]

Thanks for the fast replies guys.

I pulled the muffler and see no signs of scuffing/scoring on the exhaust side of the piston/skirt or the intake side of the cylinder wall.

Could the saw suddenly start running super rich for no reason? (I've never touched the mixture screws...)

 

[Trigger-Time]

The saw should have a one year warranty, If like me I want to fix
what I can on my own....But if still under I would take it back to
the dealer

 

[doc874]

Stihl 361

Back too the dealer quick if under warranty. Let them figure it out and fix it up. Its the least your Stihl dealer can do if they are worth their salt/pay.

Doc

 

[B_Turner]

Carp on plug?

 

[Canyon Angler]

if still under I would take it back to
the dealer

Well, that's what I did. Turned out there's a superfine-mesh screen under a screw on the starboard side of the muffler. Dealer pulled the screw, pulled out the screen and - wala - it was plugged with carbon. He heated it with a propane torch to burn off the carbon, scraped off the ash, stuck it back in – and good as new.

Might be good to try for those of you who, like me, have an uncanny sense that the 361 doesn't seem as strong as it seemed when it was new!

My Stihl dealer, and this website, RULE! Thanks again.

 

[Haywire Haywood]

How many hours do you have on the saw? You might be running it rich, which would cause the screen to clog prematurely.

Ian

 

[B_Turner]

I'd also be interested in a report back on whether the tach says you were running rich. What oil and ratio are you running?

Just curiousity.

 

[Trigger-Time]

I'd also be interested in a report back on whether the tach says you were running rich. What oil and ratio are you running?

Just curiousity.

I would like to know also. Plus how old is the saw...how much use has it seen?

Good to here you got it fixed, I bet it was a BIG RELIEVE

 

[THALL10326]

Well, that's what I did. Turned out there's a superfine-mesh screen under a screw on the starboard side of the muffler. Dealer pulled the screw, pulled out the screen and - wala - it was plugged with carbon. He heated it with a propane torch to burn off the carbon, scraped off the ash, stuck it back in – and good as new.

Might be good to try for those of you who, like me, have an uncanny sense that the 361 doesn't seem as strong as it seemed when it was new!

My Stihl dealer, and this website, RULE! Thanks again.

Awwwwwwwwwww you just ruined the hopes of alot of Husky owners, a bad report on a 361, durn you, they have been waiting for years to get a bad report on one, wink.

As to your fouled muffler screen usually only two things cause that, the saw carb is set too rich or you got too much oil mixed in your gas, both cases of rich running. Alittle hint about clogged muffler screens. They are very very easy to detect if you listen to the saw when you crank it. If you don't hear that familiar poping sound when you crank it check your screen. Number two if the saw will start and sounds a helluva lot queiter than you recalled it sounding check that screen. A screen going clogged will kill the power of the saw and finally get it to the point it won't even start. Its more common with weed trimmers than saws but clogged screens happen all the time.

 

[Canyon Angler]

Thanks guys. The saw is a 2006 I got around August, she's only seen maybe a gallon of premix so far.

I was running at 40:1 using the Stihl Super (synthetic blend?) oil but now I'm back to 50:1 in 89 octane with stabilizer, though the gas is never more than 1 or 2 months old.

The mechanic at my dealer said she's running right. Not too rich, not too much oil from what he could see. I don't know whether he put a tach on her.

I cut with her tonight, she's a HOSS again!

 

[THALL10326]

Thanks guys. The saw is a 2006 I got around August, she's only seen maybe a gallon of premix so far.

I was running at 40:1 using the Stihl Super (synthetic blend?) oil but now I'm back to 50:1 in 89 octane with stabilizer, though the gas is never more than 1 or 2 months old.

The mechanic at my dealer said she's running right. Not too rich, not too much oil from what he could see. I don't know whether he put a tach on her.

I cut with her tonight, she's a HOSS again!

You have just proved once and for all what I have said for years, those that make the saws know more than those that run them. Stihl says 50:1 they mean 50:1, not more, not less. Your clogging problems will disappear now. Glad you got her back in shape, good job..

 

[Trigger-Time]

Thanks guys. The saw is a 2006 I got around August, she's only seen maybe a gallon of premix so far.

I was running at 40:1 using the Stihl Super (synthetic blend?) oil but now I'm back to 50:1 in 89 octane with stabilizer, though the gas is never more than 1 or 2 months old.

The mechanic at my dealer said she's running right. Not too rich, not too much oil from what he could see. I don't know whether he put a tach on her.

I cut with her tonight, she's a HOSS again!

I wonder if they set the rpm by ear when you bought it.
I have a 361, before I got a tach and tried to set mine by
ear........I had it WAY to rich, this has come up before
with others setting the 361 by ear.

 

[Haywire Haywood]

I'm no 'spert, but if you totally fouled the screen with 1 gallon of gas, and your tech says that it's not running rich, I'd find a different tech..

Ian

 

[WRW]

Canyon Angler,

It might be a good idea to check the plug.

 

[outdoortype]

What happens if you toss the screen?

I've heard peolple advise to get rid of the muffler screen entirely. I would think that this would allow debris to get down into the muffler. Is this a bad idea?

 

[Haywire Haywood]

I'm told that it's actually illegal to run without one in some areas because of the fire hazard, sparks and such. I don't run one on my 346xp, but that's because a hack modded my muffler (me).

Ian

 

[THALL10326]

I'm no 'spert, but if you totally fouled the screen with 1 gallon of gas, and your tech says that it's not running rich, I'd find a different tech..

Ian

Good point there. Maybe a slight chance he had a sticking metering valve in the carb allowing alot of gas in after he cut it off. That would have made starting a bitiach though. Those valves stick at times and striaghen up on their own after some running..