McCulloch Super 250 From Erik

[Cobleskill]

I saw my bud who has the old Mac today and asked him what model it was. 610. It has the same red for choke and green for oil.

 

[GASoline71]

Al... I got the IPL's you sent. Just too lazy to email back.

Thanks buddy!

Gary

 

[GASoline71]

More dissasembly... Used a steering wheel puller, and some long 1/4-20 bolts and washers to pull the flywheel, and the side of the case off. Then took the bar oil and fuel tank off... it was pretty nasty in the fuel tank... so a shot of brake cleaner got it cleaned up for now.

Next is to get the front of the crankcase off, and pull the rod, piston, and crank out of this thing.

More to come...

Gary

 

[Al Smith]

I was concerned with the IPL's because for some reason I just couldn't get them sent .

Now that comment about a 610 Mac .They were two,the PM 610 being 60 cc and the 6-10 being a right hand start 70 cc .

The PM 610 was sold by the zillions the other not so common .THe PM 610 is one of the toughest saws ever to come down the pike .Heavy for 60 cc's but nearly bullet proof .

 

[Al Smith]

Oh say I just noticed ,that thing has an auto oiler good .

 

[Burnham]

I've got a Mac 610 myself, badged as a Montgomery Ward of all things. 'Twas the first chainsaw I ever bought. It really is bombproof. I cut one heck of a lot of firewood with that heavy old thing...running a 24 inch bar, full skip full chisel chain, regularly in wood up to and over 40 inches.

I think in the 20+ years I ran it regularly it had one carb kit put on it.

 

[Al Smith]

That model ,PM 610 will run for years with damage that would have killed the average saw .Generally it was due to a faulty oiler that carboned the screen and chewed the exhaust side of the piston .

Now the reed valvers like the featured 250 super are just about as bullet proof .Most got parked simpley because they weigh a ton .They aren't slow like a snail or anything ,just heavy .

 

[GASoline71]

Got the crank, piston and rod out tonight. Reeds look good. Piston is scored, but I got a line on a new one. Also got most of the parts ready for the media blaster. Gaskets are gonna be a bitch to find. Prolly gonna have to make most of them myself.

Al... look at the pic of the big end of the rod. The surface between the rod and the cap are not machined flat. Almost like they were "broke off" and then used that way. Is this normal for a McCulloch rod from the factory? Cuz from tearing this thing down... no one else has been in there.

Gary

 

[Al Smith]

That's called a pressure cracked rod . McCulloch pioneered that method which is used today on modern automobile engines ,Ford being one of them .

The idea is that the final honiing of the rod is more precise and the actual joint is stronger than with a machined rod plus it only fits together one way .I knew that the 125 engine used that method but wasn't aware of any others .

Oh yes and further the cracked rod prevents side movement of the rod and rod cap .

That piston although slightly scored should work,just shine it up with fine cloth and it should be fine .Looks to me like it ate some dust over the years ,not at all surprising .

 

[GASoline71]

Maybe some fine emory cloth on the piston? That would be EZPZ... then all I would need is some new rings.

That is the first rod I've seen like that. You are correct that it can only go together one way... pretty slick actually.

The bearings in this saw are in great shape... should I bother lookin' for new crank seals?

Gary

 

[Al Smith]

Had you not dissassembled it I would say the seals would or still might be okay .Since you've got them out already you'd just as well replace them .They are American standard . If you want I can cross reference them or Randy Duncan, Mike Acres several others could have NOS in stock .As close as you are I'd give Mike a call and have Paul pick them up .Consolidated Equipment ,Burnby BC .Either one might have rings .Fayeteville Equipment repair in Fayeteville NY might have them too or Bobs lawnmower in Maryland NY .

The last Mac seals I bought came from Randy Duncan .They were actually cheaper than ordering them through Kayman bearing .

 

[Al Smith]

Say not to skew the thread but I was doodling around the net on a site I seldom visit and I noticed something I felt was note worthy to mention .A certain well meaning person stuck a left hand start 10 series engine in a right hand start frame .

Now this is okay if in fact a right hand crankshaft is used .If the lefty is used he takes a chance of unscrewing the clutch nut while starting it ,no kidding . A lefty uses a left hand thread and vica versa . Might be a kind thing to mention same but subtily without mention as to the source of the info .---back to the 250 super ----

 

[Al Smith]

Seal cross reference

Now to the topic . Flywheel side seal ,Mac number 50663-replacement Chicago Rawhide 6763 . Clutch side Mac 104432---- Cr -6816

 

[GASoline71]

I will have to query on the saw you mentioned Al...

Thanks for the cross reference on the crank seals.

Gary

 

[GASoline71]

Lots of squeaky clean parts!

Gary

 

[MasterBlaster]

Sandblast em!!!

 

[Al Smith]

There's a guy that Cut and I know who puts the damned greasey things in the dish washer .I'll bet the Mrs. is proud of him .

 

[Strikermike]

Throw them in a bucket of carb cleaner for a few hours.

 

[Al Smith]

Not to sound like a wise arse but sand blasting can just eat that cast aluminum up if the correct media isn't used .It would take 40 coats of primer to fill in the voids . People have done it though and with a nice paint job they look brand new .

About the most extreme I've ever done was pressure wash them .They look good from a distance but up close not as well .About like a 50 year old lounge lizard in the "neons "

 

[NeTree]

I was thinking a tumbler with some walnut shell for a bit would work nicely.

 

[Dave Shepard]

I've made a few gaskets for things over the years. One trick I was shown was to use a 3M spray adhesive to stick the new paper to the part. Then you can cut around it making a perfectly fitting gasket. If the edges of the part are sharp, you can also tap with the ball of a ball peen hammer. I don't know if it will work on such small bolt holes, but on bigger ones you use a small ball peen and put the ball over the bolt hole and tap with another hammer. It will cut the paper like a die.

 

[Cut4fun]

I'd like to put a portable dishwasher in my barn someday. But I sure as heck aint putting nothing in the NEW dishwasher I just installed in the house. The old one was no biggie on putting stuff in, but this new one I dont want to get caught.

Them Macs are just a total different beast IMO on the tear downs etc and Thanks Al for the IPL of the 805.

 

[Strikermike]

Just get a dishwasher with a stainless steel interior. Only you will know what went through there.

 

[Cut4fun]

Just get a dishwasher with a stainless steel interior.

The new one is.

 

[Strikermike]

Alrighty then. Seems you are all set