McCulloch Chain Saws

[dieselsmoke]

And finally this old gear drive. No more decal on the AF, but is marked S 55 on the crankcase.
It runs awesome, clean inside both tanks, clean airbox. Popped the muff and it looks real nice inside. The old guy who put it away, poured 30wt in the bore. Much thanks for that.

 

[Eccentric]

I spent a lot of time in Petaluma over the years, but nothing in the past 10 or so...

Mark

Then you're due for another trip out here.

A/F lid and the decomp lever don't go together. I'm not sure what you have but I think you did well nevertheless, Ron

Muffler also looks to be from a 70cc or below saw. 82cc saws have two horizonal screws; the others have two vertical screws. Ron

Looks to me like our friend Brad has scored a clean CP-70 with an SP-81E (op pres lever) tank and AF cover.

 

[PogoInTheWoods]

SP-81 Crank Questions

I'm going to go look at a SP-81 this afternoon that supposedly has a small piece of the crank keyway broken away and it will no longer hold a key. Are the cranks tapered on these things to achieve the actual security of the fit, or is the key necessary to ensure the fit as well as the timing? (The only pic I could find of one of these cranks wasn't very helpful in making a determination one way or the other.)

TIA for any info as usual.

edit: Oh, yeah....anyone have a crank for one of these if I'm overcome by yellow fever and go ahead and buy it anyway?

 

[Eccentric]

I'm going to go look at a SP-81 this afternoon that supposedly has a small piece of the crank keyway broken away and it will no longer hold a key. Are the cranks tapered on these things to achieve the actual security of the fit, or is the key necessary to ensure the fit as well as the timing? (The only pic I could find of one of these cranks wasn't very helpful in making a determination one way or the other.)

TIA for any info as usual.

edit: Oh, yeah....anyone have a crank for one of these if I'm overcome by yellow fever and go ahead and buy it anyway?

The cranks are tapered. Get it if it's cheap enough.

PM850 crankshaft ends visible here.

SP-81 at rest.

 

[dieselsmoke]

Muffler also looks to be from a 70cc or below saw. 82cc saws have two horizonal screws; the others have two vertical screws. Ron

thanks Ron, now I wont feel so bad if I use this one up, blocking firewood.
I just checked my other SP- and they match your observation, muff screws are horizontal. Now i want to measure the blasted thing just to know the displacement. There is no tag inside the airbox.

 

[fechtichmac]

cp70

thanks ron, now i wont feel so bad if i use this one up, blocking firewood.
I just checked my other sp- and they match your observation, muff screws are horizontal. Now i want to measure the blasted thing just to know the displacement. There is no tag inside the airbox.

cp70 ??

 

[heimannm]

CP70 is a pretty good guess, not quite as powerful as an SP81 but a very nice saw none the less.

Many of the saws had RH thread on the PTO side and thus needed the key to prevent the clutch from working loose. While it is possible to have the crank shaft welded up and re-machine the key way, probably a simple solution simply find a new crank shaft. If it has RH threads the keyway must be useable, if it has LH threads chances are there is no keyway and none required to hold the clutch in place.

Mark

 

[rwoods]

dieselsmoke, other than your first post, all I get is red "x"s for your pictures. I believe Aaron is right - a CP70L with a newer tank and a SP81 a/f cover. Should be a good 70cc saw; only way to know for sure is to measure the bore and stroke as you stated. Ron

 

[homelitejim]

cp70 ??

You know......It is possible to make a CP70 a 82cc saw, just need the right donor.

[video=youtube;OuA0W9APlbE]http://www.youtube.com/watch?NR=1&v=OuA0W9APlbE&feature=endscreen[/video]

 

[PogoInTheWoods]

The cranks are tapered. Get it if it's cheap enough.

Well I picked it up for 40 bux along with a running Homie 17 grinder for another 35 plus a bunch o' parts for the Mac......, like basic hardware/fasteners, extra flywheel, coil, sprocket cover, recoil assembly, new points set, extra short bar that'll have a new home on my 10-10, coupla extra chains for both bar sizes (the Mac 8X is a 28" setup), original manual and old IPL for the Mac, a handful of 7 and 8 pin 3/8 drive rims, a 404 8 tooth drum sprocket for something, spare air filter and air box cover, bunch o' starter rope, a bad crank, and lots o' questions.

First question;

What causes enough pressure in the fuel tank to force fuel up and out of the cap vent when the damned thing is just sitting doing nothing? Burped the cap and the same thing keeps happening. Hell, the cap doesn't even need to be sealed tightly. Just loosely threaded exhibits the same thing, but around the cap threads vs. the vent if there's enough of an opening. 'Bout 3/4 tank of fuel volume in it at present.

As for my 8X reference, I'm not 100% convinced this is actually a 81SP in the first place since the air box cover isn't original according to the seller and the tank may or may not be original as well. But I'll take it anyway and figure things out as I go.

A couple of obligatory "did happen" pics. Hell, the bar and chain were worth the drive for the money. And the dude was a real nice guy and just didn't want to mess with the crank issue. Pics of that soon to come, and it's ugly, but hey...

I got a fever. And the only cure is more yellow cowbell!:help:

​

 

[heimannm]

600438 is the correct model number for the SP81.

Fuel cap issue is likely a faulty duck bill valve. Post a photo of the inside of the cap and we can tell you if it is easy to remove the stem and install a new duck bill. Bad news, NOS units are virtually unobtanium, but there is a red Homelite valve that can be used fairly easily. I think the details are buried somewhere in this thread.

If that SP81 is a good runner, you will have a new favorite saw.

Mark

 

[homelitejim]

Looks like I need to dig out my PM850 project, I thought 2 5 cube Mac's would be plenty but this thread is agravating my CAD.

 

[dieselsmoke]

dieselsmoke, other than your first post, all I get is red "x"s for your pictures. I believe Aaron is right - a CP70L with a newer tank and a SP81 a/f cover. Should be a good 70cc saw; only way to know for sure is to measure the bore and stroke as you stated. Ron

Yep, you guys are correct. I measured the stroke, crude method, but confirms its a 70cc model. The tank and handle assy have almost new paint, whereas the front/bottom do not.
I'm not complaining tho, I bought it as non-runner, figuring the parts alone justified the price. Now it runs, and runs pretty durn good.
I cant explain the red X's. I haven't been able to embed pics in post for awhile. This was a first.


Thanks for the feedback. DS

 

[Warped5]

600438 is the correct model number for the SP81.

Fuel cap issue is likely a faulty duck bill valve. Post a photo of the inside of the cap and we can tell you if it is easy to remove the stem and install a new duck bill. Bad new NOS units are virtually unobtanium, but there is a red Homelite valve that can be used fairly easily. I think the details are buried somewhere in this thread.

If that SP81 is a good runner, you will have a new favorite saw.

Mark

Mark, I have the Homelite part number as 69451.

 

[rwoods]

PogoInTheWoods, nice saw and great price.

dieselsmoke, you should get much better gas mileage with 70 ccs.

Ron

 

[paccity]

Looks like I need to dig out my PM850 project, I thought 2 5 cube Mac's would be plenty but this thread is agravating my CAD.

you can't have to many.

 

[ozflea]

you can't have to many.

Your right i have a shed full

McBob

 

[ozflea]

Just got this a Mac PM1000 PISTON AND RINGS

 

[Warped5]

I was wondering what happened to Jacob. Hope he didn't wind up in a bad spot between a rock and a boulder or something. I was a bit harsh on him a couple of times. Hope that didn't get taken too personally.

Jacob has been out of sight for some time now.

A few members were complaining recently about some 'unfinished business' with the young lad ..

 

[Mac 10-10 auto]

Bar dressing

I have the original bar on my 10-10 and I had a new chain made at the local mower place they gave me the good chipper chain but I have noticed. The top bar rail one rail is higher then the other and the gap that's suspost to be .50 is really .63. Is there any thing I can do to the bar to make sure my new chain doesn't wear uneven. Any help or tips for fixing this problem would be appreciated

Brad