Stihl 064 cracked crankcase...thoughts?

[BuckthornBonnie]

Picked up a non-running 064 from the local shop last fall. Saw has scored two p/cs according to original owner. I'm a sucker for problem saws so I grabbed it cheap. Previous rebuilds must not have cleaned the usual gunk, because I found this today:

 

[BuckthornBonnie]

I doesn't seem to be affecting the crankcase itself (can't see it looking down in the case), but i'm suspicious that this was the cause of the air leak that toasted the piston. It's close to the cylinder gasket so I'm wondering if there was enough flex while cutting to cause a leak?
Options would be:
1. Use it and pray (I don't sell saws).
2. New (used) case half... the bottom end on this saw is tight and just needed new seals.
3. New set of cases
How would you guys handle this one?

 

[BuckthornBonnie]

 

[thechainsawguy]

Number 2.

Don't use that case.

Dave

 

[drf255]

That one looks like a tough welding repair, and likely expensive.

Another vote for a used case half.

 

[glock37]

New oem case they come with bearings no gasket


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[Garth elder]

Common with 064 usually caused by leaning mixture to get more revs from them we used to remove the mixture screwdriver from the tool kit before selling them too many owners thought the more revs they could do the better that was the result later stihl released them with a red light to assist with proper setup
066 had much stronger cases it was a known fault with the 064 last forever unless overreved

 

[jmssaws]

064 and a 066 have the same flywheel side case accept a cosmetic difference.

That 064 is listed so over revving would be hard to do.

I'm not seeing that cause a airleak but hard to say where it is on the inside.

 

[Ted Jenkins]

Just last summer I tried in vain to do some case repair. As a matter of fact I was sure with the right effort it could be done. Three times I set up my mig and tig, but no go. The welded area became very very britle. But NO. If epoxy will not work chuck it. I have seen 066s on ebay. Or just order a new OEM at what ever the cost or part it out. Welding is not the answer. The alloys used are not weldable. Thanks

 

[glock37]

Get hold of sean hes the case welder around here


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[blsnelling]

That 064 is listed so over revving would be hard to do.

Only 064s with the CDIC coil are rev limited. Many are not.

 

[jmssaws]

Only 064s with the CDIC coil are rev limited. Many are not.

That one is cdic
Looks at the coil

 

[jmssaws]

I didn't see a limited one for years and I port a bunch of 064's but lately everyone I get in the shop is limited.
I got a box of coils and flywheels if for some reason somebody wants one

 

[BuckthornBonnie]

This saw is cutting wood with a set of cases from morningman.

It was limited, but an 046 coil and 1201a flywheel solved that.

 

[jmssaws]

This saw is cutting wood with a set of cases from morningman.

It was limited, but an 046 coil and 1201a flywheel solved that.

I wish I had a truck load of unlimited flywheels.

I have lined up the magnets on a limited and unlimited flywheel and mark the key way and run it without a key and it works just fine

 

[jmssaws]

I wish I had a truck load of unlimited flywheels.

I have lined up the magnets on a limited and unlimited flywheel and mark the key way and run it without a key and it works just fine

It's actually very easy to do.

 

[BuckthornBonnie]

Do you have any experience with the AM dogleg coils?

 

[jmssaws]

I've never tried one.
Most are dual drilled so any coil will work