Rode hard & Put up wet

[hotshot]

Should I try to use JB Weld to patch this up, lol? Everybody loves carnage, when it’s not your own!

This Stihl 056 magnum II had the PTO side bearing balls all stacked up together from the failure of the “engineered polymer” ball ribbon...I hate plastic parts.

The steel wrist pin is so worn out it moves up & down about 0.050” in both the WP bores, plus the skirt is in five pieces in the crankcase sump.

It will live again though, with new bearings & new OEM top end, as the PTO bearing did not spin in the bore.

 

[pioneerguy600]

I hear they make a good device to prevent watercraft from drifting.

 

[hotshot]

Or an ashtray for the stubby Colorado sourced cigars.

 

[Huskybill]

Old piston are great for pencil holders, plus it reminds us of things that woreout from hard work. It’s a good thing to look at when we get old. History and stories for the grandkids.

I never thought about welding that up for another life? Lol

 

[hotshot]

Suspect someone killed it by running bad gas or old gas, as the piston crown top is rat chewed off on the exhaust side.

Rings and WP bearing were not damaged, but won’t be reused. Case, crank & rod ends are fine. Go figure.

 

[s sidewall]

View attachment 722504

Should I try to use JB Weld to patch this up, lol? Everybody loves carnage, when it’s not your own!

This Stihl 056 magnum II had the PTO balls all stacked up together from the failure of the “engineered polymer” ball ribbon...I hate plastic parts.

The steel wrist pin is so worn out it moves up & down about 0.050” in both the WP bores, plus the skirt is in five pieces in the crankcase sump.

It will live again though, with new bearings & new OEM top end, as the PTO bearing did not spin in the bore.

OOOOO, pretty, glad that wasn't mine.

Steve

 

[pioneerguy600]

Suspect someone killed it by running bad gas or old gas, as the piston crown top is rat chewed off on the exhaust side.

Rings and WP bearing were not damaged, but won’t be reused. Case, crank & rod ends are fine. Go figure.

View attachment 722513

Many mechanics I worked around thought that it was water droplets from old bad fuel hitting a hot piston crown that caused this, I was never totally convinced of that as the fuel also comes into contact with the underside of the piston first and I have yet to see pock marking on the underside of a piston. Does this eroding happen on the top side of the crown due to compression of the mix?

 

[HarleyT]

Cheap Homeowner junk!!!

Should be covered under warranty!!!

 

[hotshot]

Many mechanics I worked around thought that it was water droplets from old bad fuel hitting a hot piston crown that caused this, I was never totally convinced of that as the fuel also comes into contact with the underside of the piston first and I have yet to see pock marking on the underside of a piston. Does this eroding happen on the top side of the crown due to compression of the mix?

I don’t know, but I’m thinking preignition erosion causes those micro pits/pockets, and that is due to the octane loss in old stale fuel & a lean mixture.

The piston has a huge black “spot of death” under the crown, and carbon was caked up everywhere for making hot spots.

Wouldn’t take a couple of tanks of foul gas on a hot day to do that, plus with all the chain & clutch noise, you’re not going to hear it pinging like a car.

They’re just powered hand tools, run ‘em like you stole it!

 

[pioneerguy600]

I don’t know, but I’m thinking preignition erosion causes those micro pits/pockets, and that is due to the octane loss in old stale fuel & a lean mixture.

The piston has a huge black “spot of death” under the crown, and carbon was caked up everywhere for making hot spots.

Wouldn’t take a couple of tanks of foul gas on a hot day to do that, plus with all the chain & clutch noise, you’re not going to hear it pinging like a car.

They’re just powered hand tools, run ‘em like you stole it!

Interesting, I never had one in my own hands to examine, not one saw that ever came my way had this type of damage. Others have seen an odd one so it does happen but I would think the saw would be acting very strange and be real low on power it it ran on fuel that bad.

 

[hotshot]

Lol, hope I never see another one!

Definitely heat related though, as the location of the pits borders all along the exhaust port side.

 

[pioneerguy600]

I bet it will be a good runner when finished up, its one class of Stihls I have never run or owned. They look bulky and heavy.

 

[hotshot]

They cut well, but yes they are heavy on today’s scale. Only use them for felling & bucking big trees.

I got hooked on a pair of them 20 years ago during clearing out large oaks for dock road building on lake property.

Of course they have multiplied a lot over the years...I do have CAD.

 

[67L36Driver]

I bet it will be a good runner when finished up, its one class of Stihls I have never run or owned. They look bulky and heavy.

Just weighed one. 056 w/30”, full of fuel & oil. 25# 7 0z

Definitely not a climbing saw.

 

[pioneerguy600]

Just weighed one. 056 w/30”, full of fuel & oil. 25# 7 0z

Definitely not a climbing saw.

That`s not heavy, worked with much heavier bone rattlers back when. Heavy by todays standards though and no , nothing heavier than a Stihl 044/MS440 for climbing, a 50 cc saw will do 90% of climbing work for me.

 

[hotshot]

Just weighed one. 056 w/30”, full of fuel & oil. 25# 7 0z

Definitely not a climbing saw.

That’s spot on for weight, and coupled with the great anti-vibe bushings they’ve got, it’s like sawing on cruise control, lol.

Those big cube saws are like the outhouse. Go unused for most of the time.

You don’t need them around much, but when you do, you need it really bad!

 

[pioneerguy600]

I like my 090, I don`t need to lean on it.

 

[hotshot]

Almost home, new all steel carrier FAG bearings, passed vac & pressure tests, and has great spark ️. Oven baked the halves at 300F to seat the bearings, then sucked the crank ends through with squared end pipe sleeves, washers & nuts...redneck, but it works well.

Easier to grind & bevel off the piston crown than to lower the exhaust port I thought, plus trimmed the piston skirt on the intake some too. Got a bit more duration in & out. Went back with a good used top end, Caber rings & OEM wrist pin bearing.

150# with new rings & assembly oil, but that’s about all the plastic starter pawls will take.

 

[67L36Driver]

Note to self:

Remember the rubber band trick. [emoji6]

 

[hotshot]

And those four headless 5mm screws, to keep the case halves from rotating...makes it less of a fight.