Yet again .... JMSSAWS strikes

[Chainsaw Jim]

Ryans :
View attachment 85892

There's no way in hell he's that good at shaving a crank balance. They do stuff like that at the factory. Here's one of mine that came from a stock 660.

 

[Deets066]

There's no way in hell he's that good at shaving a crank balance. They do stuff like that at the factory. Here's one of mine that came from a stock 660. View attachment 85903

There was nothing good that I saw in the pic

 

[mdavlee]

I kind of think like Jim. The crank is way harder than the piston. Now way the piston did that without coming apart in there.

 

[Deets066]

@Moparmyway, what does the piston skirt look like?

Does that coinside with your assumption?

 

[Sleeper]

EDIT: Apparently someone shows a picture of a crank out of a unmolested stock saw... looks the similar to me.

 

[hoskvarna]

Wont that unbalance the crank to the point of takin out the bearings ?


Sent from Hoskvarna Hills

 

[Sleeper]

Learn stuff almost every day. Interesting how they balance the crank... never seen that before. None of my Macs were shaved balanced like that.

Another book I think everyone interested in engines (and the history of outboards and inboard/outdrives/sterndrives) should read is "The Legend Of Mercury" by Jeffery L. Rodengen

Gives the whole story of Carl Kiekhaefer and how Mercury came to life. Great read, just got done with it and learned a lot.

 

[Mastermind]

I kind of think like Jim. The crank is way harder than the piston. Now way the piston did that without coming apart in there.

Good Point.....

 

[Moparmyway]

Is it useable Kevin?

@Moparmyway, what does the piston skirt look like?

Does that coinside with your assumption?

The skirts have been mostly polished away, but what happened to that crank, I'm not sure that the piston didn't do that. I've got 4 cranks from 1122's to view, one new and 3 very used. Also have 2 cranks from 1128's. They all look the same, marks from spinning them in a lathe.

The chatter marks are only on this one crank.
I'm certainly not going to try to say that I'm sure, but it definitely stands out

 

[Mastermind]

The skirts have been mostly polished away, but what happened to that crank, I'm not sure that the piston didn't do that. I've got 4 cranks from 1122's to view, one new and 3 very used. Also have 2 cranks from 1128's. They all look the same, marks from spinning them in a lathe.

The chatter marks are only on this one crank.
I'm certainly not going to try to say that I'm sure, but it definitely stands out

It would surely have aluminum transfer on it if it was making that much contact.

 

[drf256]

This looks like something hit it that was threaded.

 

[drf256]

My bet is that those marks are from the first time the saw blew up.

We all seem to forget the saw was redone twice.

I'm sure he cleaned nothing after the first wrist pin blew.

Probably lots of crap peening that crank.

 

[Moparmyway]

Then the good news is that my initial thoughts are probably dead wrong, thanks to Jim, Mike, and Randy. This also means that the crank is fine and I'll be able le to use it without any worries

Thanks men !!


Edit: Could the blown rod bearing have caused the pitting like Doc @drf256 hypothesizes ?

Does anyone have a new crank that isn't used that has these marks ?

I do understand that Jim @Chainsaw Jim has that crank, but it is used, and is it possible that it had an event prior to it being removed ?

 

[blsnelling]

There's no way an aluminum piston removed metal from a steel crank.

 

[Mastermind]

My bet is that those marks are from the first time the saw blew up.

We all seem to forget the saw was redone twice.

I'm sure he cleaned nothing after the first wrist pin blew.

Probably lots of crap peening that crank.

I think the color would be different in any damaged areas.

 

[blsnelling]

My bet is that those marks are from the first time the saw blew up.

We all seem to forget the saw was redone twice.

I'm sure he cleaned nothing after the first wrist pin blew.

Probably lots of crap peening that crank.

My money is that it's from the factory like that. The patina is the same across the entire crank.

 

[Chainsaw Jim]

Then the good news is that my initial thoughts are probably dead wrong, thanks to Jim, Mike, and Randy. This also means that the crank is fine and I'll be able le to use it without any worries

Thanks men !!


Edit: Could the blown rod bearing have caused the pitting like Doc @drf256 hypothesizes ?

Does anyone have a new crank that isn't used that has these marks ?

I do understand that Jim @Chainsaw Jim has that crank, but it is used, and is it possible that it had an event prior to it being removed ?

Here's a close up of an original 1100cd big end.


That little thread mark spot Al pointed out up above is definitely not from the factory and could not be from anything other than Jason dropping it on a concrete floor on top of a screw or swapping the new unblemished one for the one pictured.

 

[paragonbuilder]

My money is that it's from the factory like that. The patina is the same across the entire crank.

It also looks very consistent. And don't forget the piston would only hit the crank in one small area. Not the whole surface. If it was damage, I would think the wristpin bearing parts in the bottom of the case, but you would see that in the case when you split it, and I don't think the motor would have ran but a few moments with all that crap in there.
I'm with Brad on this one.


Sent from my iPhone using Tapatalk

 

[Moparmyway]

Cases split, bearings and seals out, new bearings and seal kit on the way (thanks to a very generous forum member). One bearing had some rough spots as you spun it. Good thing here is that this new saw will have new bearings and seals along with a NIB P&C.

More buggered stuff too .......

 

[Czed]