What is this funk?

[Wilhelm]

Maybe I should just split the case to inspect whats going on.

Seems like only logic thing to do.
Cleaning will also be much easier once completely taken apart.

 

[Lee H]

You will want to split the cases to clean it all out. Possibly replaces bearings and seals
as well. Although the few I have seen in this condition or worse the steel holds up well.
Seems the reaction is only with the magnesium and doesn't affect the steel components
really at all.

 

[MrWhoopee]

Seems the reaction is only with the magnesium and doesn't affect the steel components really at all.

On the nosie. The mag acts as a sacrificial anode. It corrodes, while protecting the steel. It's the same principal as galvanizing, the steel is protected from rusting, even when the zinc coating is breached. Large zinc posts are placed in the water around ships in mothball storage, with a wire connecting them to the ship. Greatly reduces corrosion of the steel while the zinc is eaten away. This electrolytic reaction is the reason that dissimilar metals (ie. steel and aluminum) are not used in direct contact in wet environments. The aluminum goes away.

 

[Brush Ape]

trooney if you take it ice fishing again, cut holes from above the ice next time.

 

[Al Smith]

You can see the same thing on aluminum screen doors,sliding patio doors etc .The aluminum front cover bolts on Ford 460 engines would bind up tight as a bulls azz in fly time after about 20 years .Plated bolts had some effect but I always coat the screws with Never Seeze or Kopper Kote on reassembley on chainsaw engines .
The saw in question will probably be okay once it's cleaned up .As I type I have a Partner P-100 that has some of the same problems ,just haven't had time to rebuild it yet .

 

[Adirondackstihl]

Gonna wanna split those cases.
I wouldn't run those bearings.
Big end bearing prolly don't look good either

 

[trooney]

I'll split em this week. Kinda interested to see what the insides look like.

 

[trooney]

Well I got it apart. This heres the damage. Any ideas how to clean it up? Suggestions? Or is it a lost cause. The crankshaft still turns but you have cement basically on the crank. Not the worst but it might have been better.

 

[dall]

i dont see any pictures tom

 

[trooney]

 

[trooney]

Now you do! Lol

 

[dall]

do you have a ultrasonic cleaner tom may try cleaning the parts

 

[trooney]

Yeah, I was going to suggest that. You think it will work?

 

[dall]

worth a try nothing to lose

 

[Onan18]

Cases are fugly, only way to save them now is blasting and new powder @Glock37 Crank might clean up in an USC, worth a try at least.

Joe

 

[Mastermind]

This saw is a fine one to stress test an aftermarket crank and bearings in Tom.

 

[trooney]

This saw is a fine one to stress test an aftermarket crank and bearings in Tom.

Yeah, what I was thinking. It'd be a good saw to tinker around with.

 

[Mastermind]

I did a well worn 200T with am crank. So far so good.

 

[trooney]

Well, just pulled the crank from the US. I'm pretty happy with the results. What do you think Dallas?

 

[trooney]

The crank doesnt have any pitting either which is real good.