Internal crankcase question

[Mark71gtx]

I recently picked up on 038 Magnum. It was filthy like almost every saw he brings... I opened it up and there was standing water in the crankcase. I plan to split it and replace the crank, bearings, and seals. What can, or should I do to the "engine" portion of the crankcase, other than make sure it is clean? Make sure everything is smooth and paint it?

 

[Mark71gtx]

Not what I wanted to see when I pulled the top end off...

 

[Adirondackstihl]

Better find a new crank at bare minimum

 

[Mark71gtx]

Got new crank, seals, and bearings. I just want to know what to do to the inside of the halves, if anything.

 

[jacob j.]

Wire brush and sand the mixing area out smooth. I used wire brush attachments in my die grinder and then finish it off wet sanding with 220 and 400 grit and WD-40 or Liquid Wrench. It leaves a nice, smooth finish.

You'll want to get all the corrosion out along with any loose powder coating.

 

[Mark71gtx]

Should I try to paint it once I have it smooth, or is bare inside okay? I know magnesium has a tendency to disappear if left uncoated. Maybe the oil from the mix is enough to keep it from messing up?

 

[Tor R]

I got one 254 who had been filled with water for years.
Crankcase was in badly corrussion state, what i could use was cyl, carb,flywheel,heathed handle and a few other parts.
Have you split the case?

 

[smokey7]

Wow that's rough. I'd like to see a time bomb and run it till it blows

 

[angelo c]

wonder what @Glock37 (mike) might do with the halves once they were apart. maybe powder coat the crankcase inners ?

 

[Mark71gtx]

I have not split it yet. Here is the actual timeline of events. I repaired two 026's and a 361. I was given 2 290's and the 038 Mag for payment. Took 2 290's and made a really nice one. A buddy at work will be picking it up soon. 038 was locked up with no muffler. Piston looks good, so I spray seafoam deep creep in plug hole and on exposed side of piston. Wait two hours and rotate the crank with a ratchet. Feels decent. Put some fuel in and mount recoil. Pull ten times with no hit. Pull plug to see if it is getting fuel, and it looks like coffee with creamer... Tear down majority of saw. Ask you all for advice... I will be removing the clutch and splitting the saw in the very near future. I want to finish the 650/660 before I split another one though.

 

[Mark71gtx]

Wow that's rough. I'd like to see a time bomb and run it till it blows

I'll send you the crank and bearings if you have an 038 case you want to wreck... I don't want to screw up this Magnum case...

 

[smokey7]

Nope no saw like that here

 

[Motorhead]

Not what I wanted to see when I pulled the top end off...View attachment 10466

Fill it full of automatic transmission fluid and let it sit for a week,Then check it out.

 

[jacob j.]

Should I try to paint it once I have it smooth, or is bare inside okay? I know magnesium has a tendency to disappear if left uncoated. Maybe the oil from the mix is enough to keep it from messing up?

Regular paint won't hold up to the heat and petroleum exposure. Just leave the inside bare unless you want to have it powder coated (Stihl and Husqvarna cases are powder coated at the factory). The continual coating of oil will protect any bare Magnesium.

wonder what @Glock37 (mike) might do with the halves once they were apart. maybe powder coat the crankcase inners ?

Mike would do an excellent job and that would be my preference if I were doing a full restoration.

 

[beaglebriar]

I'd probably go with powder coating but that depends on how much you want to spend on it.

 

[Mark71gtx]

Not a full restoration. I already have an 038AV and another 038 Magnum. It will likely find a new home once I am done with it. Of course, I say that about a lot of things that are still here...

 

[Mark71gtx]

Looks pretty bad on the flywheel half. Not too bad on the clutch side. It is currently in the ultrasonic washer taking a much needed bath.

 

[angelo c]

Looks pretty bad on the flywheel half. Not too bad on the clutch side. It is currently in the ultrasonic washer taking a much needed bath. View attachment 10656 View attachment 10657

Not terribly attractive...

 

[Backyard Lumberjack]

I have not split it yet. Here is the actual timeline of events. I repaired two 026's and a 361. I was given 2 290's and the 038 Mag for payment. Took 2 290's and made a really nice one. A buddy at work will be picking it up soon. 038 was locked up with no muffler. Piston looks good, so I spray seafoam deep creep in plug hole and on exposed side of piston. Wait two hours and rotate the crank with a ratchet. Feels decent. Put some fuel in and mount recoil. Pull ten times with no hit. Pull plug to see if it is getting fuel, and it looks like coffee with creamer... Tear down majority of saw. Ask you all for advice... I will be removing the clutch and splitting the saw in the very near future. I want to finish the 650/660 before I split another one though.

> Pull ten times with no hit

if all that looks like it does, no reason to think the carb is any good in current condition. if u got compression... if you got spark.... put some carb cleaner down into it, thru carb... see if it will pop off. if it wont pop off on carb cleaner... keep huntin'...

btw, be sure to let us know what kept it from at least popping off? always interesting to learn...

 

[Al Smith]

From the looks of things what you see is galvantic reaction between the steel bearings and crankshaft and the aluminum case .

I've got a couple of cases from 038 av's but without modifications they won't fit a mag .Probably with a little bit of elbow grease those will clean up .