MCCULLOCH The official McCulloch thread

[hacskaroly]

Got the SP81 apart today.

Looks like my D44, all apart, cleaning it up. Had to fill a hole that developed in the oil tank. I need to get some parts that hold the fuel wick down, but otherwise, it looks to be in really good shape and I am excited to get it cleaned up and back together!

 

[hacskaroly]

I press the bearing and seal out of the insert, and press new ones in with a mandrel through the bearing to insure it does not tweak the cup.

Are those homemade tools?

 

[heimannm]

Yes, I made them specifically for this task. The large piece holds the insert securely, the smaller mandrel will press the bearing and seal out, the larger one insures they are seated in the proper location. The I.D. of the mandrel is precisely 9/16" (just like the crankshaft) to prevent any distortion of the bearing housing (cup) as the bearing is pressed out and in again. I learned this lesson the hard way just pressing the bearing without the internal support.

I also made a tapered sleeve to aid in slipping the assembled bearing/seal/insert onto the crankshaft. Without the sleeve, the lip of the seal tends to catch on the shoulder of the crankshaft making it very difficult to slide the seal past the shoulder.









Mark

 

[Sloa]

Not sure if chart will show and hope I say this well. Mark you showed this chart of sdc carbs. I would like to change my sdc 2 on super 6-10 to the sdc18. I have two questions. First when I locate one is it a direct swap with lock plate linkages and h/l.
I love the saw but feel it can give more. Second the s6-10 shares sdc18 carb with cp class saws and 7-10a, but does not on other carbs used on 7-10. Would they not be candidates I could choose from.

 

[Steve]

Yes, direct swap. My s6-10a came with the sdc18. My 7-10 had a tillotson HS carb but I can't remember the number. I like the tillotson because in my experience it is a better tuning carb.

The sdc2 is a small venturi carb for the 54cc saws but mcculloch being mucculloch did put them on the 70cc saws on occasions because that's what they had that day.

 

[heimannm]

Show us a pic of the little red barn piston! The old ones I don’t think would even run!, It looks like they have an updated piston that might have some chance of running

SP125 pistons have arrived from LRB. OEM on the right, LRB on the left.











Mark

 

[heimannm]

I joined them with a wrist pin to see how the heights compared.





OEM



LRB



Mark

 

[Bigmac]

View attachment 427912

I joined them with a wrist pin to see how the heights compared.

View attachment 427913

View attachment 427914

OEM

View attachment 427915

LRB

View attachment 427916

Mark

That looks pretty decent Mark, does the wrist pen have a plug in the end like the OEM?

It looks like it has thicker rings, and recessed pin boxes with a more modern style ring that overlaps the pin boss? If that’s all true, it should have better ring seal and make a little more compression.

 

[heimannm]

The wrist pin supplied with the LRB piston was not useable for this saw, open both ends and too short.



I did have to shorten the original wrist pin a bit to allow the circlips to fully seat in the grooves. Original was 2.015" long.



I reduced it to about 2.002" long.



Circlips now seat fully.





I am going to use the circlips supplied with the piston as part of the test but I did make sure to locate the ears at TDC to minimize any chances it will work loose due the the reciprocation of the piston.

Mark

 

[heimannm]

My iron bore cylinder was just over the limit for bore size, and nearly 0.001" out of round with the larger diameter as you would expect due to the action of the crankshaft and connecting rod. Spec's say 2.2805/2.2795" and mine is about 2.281"+ 90° to the wrist pin, 2.280"+ parallel to the wrist pin.

Turns out the piston, to the best of my ability to measure it, is also almost 0.001" out of round at the skirt and is actually a bit oversize just where I needed it to be to match the bore.

Ring end gap measures 0.021.





Piston parallel to the wrist pin was right on spec. 2.273/2.272" at the top.





Mark

 

[heimannm]

Spec's say 2.2755/2.2745" at the skirt. Actual was pretty much the same as the top @ 2.273"



90° to the pin it measures slightly larger at the top, almost 2.274"





Mark

 

[heimannm]

At the skirt I get just over 2.2755"





I'd always been taught that pistons were supposed to be slightly oval to account for differences in expansion due to different cross sectional areas but I don't recall ever seeing it measure out quite as precisely as this one.

Lastly, I was not going to reuse the original, buggered up rod cap bolts.



Last week I set up my Dremel as a tool post grinder in the lathe in order to rework some 6-40 screws for the oiler adjuster on a 300 Series saw. While I was at it I added a bit of a chamfer on some new 10-32x5/8 SHCS's I had on hand to provide the necessary clearance.





If this saw runs O.K. I will use it for demonstrations here on 10 August and again in Baraboo the following weekend. After that I will probably just add it to the display as I don't have an iron bore model up there yet.

Mark

 

[Steve]

At the skirt I get just over 2.2755"

View attachment 427961

View attachment 427962

I'd always been taught that pistons were supposed to be slightly oval to account for differences in expansion due to different cross sectional areas but I don't recall ever seeing it measure out quite as precisely as this one.

Lastly, I was not going to reuse the original, buggered up rod cap bolts.

View attachment 427963

Last week I set up my Dremel as a tool post grinder in the lathe in order to rework some 6-40 screws for the oiler adjuster on a 300 Series saw. While I was at it I added a bit of a chamfer on some new 10-32x5/8 SHCS's I had on hand to provide the necessary clearance.

View attachment 427964

View attachment 427965

If this saw runs O.K. I will use it for demonstrations here on 10 August and again in Baraboo the following weekend. After that I will probably just add it to the display as I don't have an iron bore model up there yet.

Mark

So what your saying is you'll let make a cut with it on the 10th? You know, for science and stuff.

 

[heimannm]

Absolutely. I may even let you man one end of a model 99 two man saw.

Mark

 

[Steve]

Absolutely. I may even let you man one end of a model 99 two man saw.

Mark

Sounds dangerous. I'm in!

 

[the 28inch mac man]

Does anyone here have mcculloch bar and chain literature ? I'm trying to find out the link count on a mac 40 inch roller nose bar.

 

[heimannm]

It's alive!

I was actually quite impressed with the way it cuts. Nothing really special about the chain, same set up I used on the 797 last week. Maybe the oak log is getting soft.







I put together some pulse and fuel line kits for the big saws and thought I'd "prove" them on this saw.



Mark

 

[heimannm]

I looked through a few old McCulloch Bar and Chain catalogs and do not find any 40" roller nose bars listed.

Mark

 

[Bigmac]

I looked through a few old McCulloch Bar and Chain catalogs and do not find any 40" roller nose bars listed.

Mark

I have a 40 inch roller nose, I think it’s a general, you have seen in action! Lol

 

[Squareground3691]

I have a 40 inch roller nose, I think it’s a general, you have seen in action! LolView attachment 428227View attachment 428228

I know those pants,Lol