MS361 Cylinder base cracked/separated......anyone ever seen this before?

[PogoInTheWoods]

This cylinder came off the saw this way. Piston and rings look fine except for normal wear. Same for the inside of the cylinder. Any thoughts on how this could happen? I'm certainly scratching my head over it...:msp_confused:

It came from a tree service guy who is pretty hard on his stuff, but there aren't any signs of it being dropped, run over, or anything along those lines. He did take it to a local Stihl shop who told him it was "burnt up". And fwiw, one of the base bolts was very loose, but the other three were torqued down tight and there wasn't any evidence of the cylinder being removed prior to me pulling it.

I'm wondering if maybe the casting had a hairline crack and I pushed it over the edge by using the "rope in the jug" piston stop method when trying to loosen the flywheel nut?

Thoughts and comments welcomed....and a MS361 jug if anyone happens to have a spare just laying around collecting dust!

​

 

[Scandy14]

That will buff out......lol. No, I can't say that have ever seen that before.

 

[cutforfun]

First two piece head i have seen done that way

 

[Justsaws]

Maybe a year or so ago I saw an 084 that was broken in a similar fashon. Rope in the cylinder in order to remove the clutch and repair the oiler. They used a breaker bar on the clutch. Popped the cylinder.

One loose cylinder mount and three were still torqued.

Saw ran before the bench beating, P/C WERE minty fresh. Piston was reuseable.

Ropes are for starters.

Piston stops are paper weights.

 

[67L36Driver]

Looks like a fatigue failure starting at the corner of the transfer port. Crack progressed over time as the surface is dark/dirty untill there was not enuff material holding it and it ruptured abruptly. Clean shiny break at the end.

I would think it would have sucked air and caused trouble earlier.

I have a perfect cond. Lombard jug that some idiot broke the corner off of by useing an object above the piston but failed to remove one nut.

I'll vote the rope trick.................................................................

How's that for changing my mind half way thru...............................................

 

[Joe Kidd]

Cast zinc will do that. :msp_tongue: Trade it for a 562xp. Sorry, just yankin' your chain!

 

[o8f150]

jb weld

 

[PogoInTheWoods]

Saw ran before the bench beating, P/C WERE minty fresh. Piston was reuseable.

This one barely pulled 60psi when it hit my bench, so the problem was already there to the extent of no compression for some reason and a blip or two with an impact wrench certainly wasn't gonna bust the flywheel nut loose. I'm putting my money on the base already being cracked.

 

[SawTroll]

Looks like a fatigue failure starting at the corner of the transfer port. Crack progressed over time as the surface is dark/dirty untill there was not enuff material holding it and it ruptured abruptly. Clean shiny break at the end.

..........

It looks that way, but it could be just the lighting in the picture?

Btw, is this a Mahle cylinder?

 

[PogoInTheWoods]

Btw, is this a Mahle cylinder?

Yep...OEM.

 

[pilgrim5]

This cylinder came off the saw this way. Piston and rings look fine except for normal wear. Same for the inside of the cylinder. Any thoughts on how this could happen? I'm certainly scratching my head over it...:msp_confused:

It came from a tree service guy who is pretty hard on his stuff, but there aren't any signs of it being dropped, run over, or anything along those lines. He did take it to a local Stihl shop who told him it was "burnt up". And fwiw, one of the base bolts was very loose, but the other three were torqued down tight and there wasn't any evidence of the cylinder being removed prior to me pulling it.

I'm wondering if maybe the casting had a hairline crack and I pushed it over the edge by using the "rope in the jug" piston stop method when trying to loosen the flywheel nut?

Thoughts and comments welcomed....and a MS361 jug if anyone happens to have a spare just laying around collecting dust!

​

Was a casting flaw right from the factory if you look at the dirty part its been an on going crack for as long as the saw has been made! The dirty part tells the real story its old and shows gas n oil leakage going on for a very long time and over the life of the saw it just kept growing the crack till it let go.

 

[67L36Driver]

Was a casting flaw right from the factory if you look at the dirty part its been an on going crack for as long as the saw has been made! The dirty part tells the real story its old and shows gas n oil leakage going on for a very long time and over the life of the saw it just kept growing the crack till it let go.

You changed my mind again...............................

 

[Saw Dr.]

I'd be calling Stihl tech support and seeing if there is any chance of a goodwill replacement on that one. It sure looks like a casting defect to me. You never know.

 

[PogoInTheWoods]

I'd be calling Stihl tech support and seeing if there is any chance of a goodwill replacement on that one. It sure looks like a casting defect to me. You never know.

A plain ol' guy like me can just call em?

 

[John_DeereGreen]

Send Stumpy a PM, my 361 did something very similar after porting.


Sent from my iPhone using Tapatalk

 

[rullywowr]

A little of this and it will be just fine:

View attachment 264212

 

[sefh3]

A plain ol' guy like me can just call em?

I think you can go to Stihlusa.com and inquire about it that way. There is a section for technical questions.
Contact STIHL

 

[SawTroll]

Yep...OEM.

Not all OEM cylinders are Mahle. If it is mahle, it will say that in clean text on it.....

 

[Mastermind]

Yep.....that will throw off the ol' sideways balance.

 

[nmurph]

A plain ol' guy like me can just call em?

Just tell'em the SawDoc sent you. They won't even ask for the secret handshake.:cool2: