MCCULLOCH The official McCulloch thread

[Bigmac]

Here is the initial result from replacing the 800 muffler with a simple square tubing L. It seems to have a little more go. A little sheet metal might end up necessary for replacing the directing of cooling air flow.

I have the sp80 at around 16 seconds
The stock 800 at 21 seconds
And the modded 800 at 17seconds

I don’t know how interchangeable things are for this series, but you can definitely hear the flywheel fan on the 800, I know they have more fins than the SP 80 and 81, not sure if that’s worth a second or more

 

[heimannm]

10 Series 12, 18, and 24 fin flywheels



The SP80/81 were 12 fin flywheels.



The PM850 were 24 fin flywheels.



The PM800 Series saws were 18 fin flywheels but with longer fins.



The RH start flywheels were also 12 fin but were slightly small in diameter and had no provisions for the starter pawls.



And there's your McTrivia for the day.

Mark

 

[Bigmac]

10 Series 12, 18, and 24 fin flywheels

View attachment 426855

The SP80/81 were 12 fin flywheels.

View attachment 426851

The PM850 were 24 fin flywheels.

View attachment 426852

The PM800 Series saws were 18 fin flywheels but with longer fins.

View attachment 426853

The RH start flywheels were also 12 fin but were slightly small in diameter and had no provisions for the starter pawls.

View attachment 426854

And there's your McTrivia for the day.

Mark

Do they all interchange?, Besides the right hand starts.

 

[Squareground3691]

Here is the initial result from replacing the 800 muffler with a simple square tubing L. It seems to have a little more go. A little sheet metal might end up necessary for replacing the directing of cooling air flow.

Definite improvement

 

[heimannm]

No, the 12 and 24 are interchangeable but the 18 with the longer fins requires a different crankshaft, unique to the 800 models (PM800, 805, DE80, and the 8200).

If I remember correctly the 800 crankshaft is a bit shorter on the FW end and also requires a different starter shaft, or maybe the FW/starter housing makes up the difference, I don't have the all details locked away in my head...

Mark

 

[heimannm]

Since the SP125 was a bust, I went to work on the first of the 797 lot. It is pretty rough on the outside but feels like it has decent compression.







I've run into a roadblock as I cannot get the crankshaft out. As you can see, the notch in the crankcase is TDC, but the piston and rod don't move quite far enough to clear the crankshaft and I have been unable to understand how the crankshaft is supposed to come past. Makes me wonder is there is some carbon accumulation in the top of the cylinder/piston and it is not moving far enough???



On the 125 the notch for the throw is slightly offset making it pretty easy to get the crankshaft properly aligned so it will pull out.



Any help here will be greatly appreciated.

Mark

 

[Bigmac]

Make sure the spark plug is out, I would also rotate back to bdc, and see if a needle is up there or piece of junk. It should move up enough

 

[jacob j.]

Since the SP125 was a bust, I went to work on the first of the 797 lot. It is pretty rough on the outside but feels like it has decent compression.

View attachment 426896

View attachment 426897

View attachment 426898

I've run into a roadblock as I cannot get the crankshaft out. As you can see, the notch in the crankcase is TDC, but the piston and rod don't move quite far enough to clear the crankshaft and I have been unable to understand how the crankshaft is supposed to come past. Makes me wonder is there is some carbon accumulation in the top of the cylinder/piston and it is not moving far enough???

View attachment 426899

On the 125 the notch for the throw is slightly offset making it pretty easy to get the crankshaft properly aligned so it will pull out.

View attachment 426900

Any help here will be greatly appreciated.

Mark

Make sure the spark plug is out, I would also rotate back to bdc, and see if a needle is up there or piece of junk. It should move up enough

In addition, I would check through the exhaust with everything at BDC to see if a broken ring is hanging things up. If this one has the thick rings - Sometime the ring locating pins on the thick ring pistons would come out and snag the cylinder wall, so it may be a gouge that's hanging you up.

 

[heimannm]

 

[heimannm]

I tried soaking the assembly in Mean Green solution for a few hours then worked the piston up in the bore as best I could. With a little "urging" I was able to get the crankshaft in position and it came right out.

Nate - plug was out, needles accounted for...

JJ - thin rings, pins in place

I am sure it was the accumulation of carbon on the crown of the piston that was preventing the piston from moving up far enough to allow the rod to clear the crankshaft.



Mark

 

[Bigmac]

I tried soaking the assembly in Mean Green solution for a few hours then worked the piston up in the bore as best I could. With a little "urging" I was able to get the crankshaft in position and it came right out.

Nate - plug was out, needles accounted for...

JJ - thin rings, pins in place

I am sure it was the accumulation of carbon on the crown of the piston that was preventing the piston from moving up far enough to allow the rod to clear the crankshaft.

View attachment 426941

Mark

Great Mark, always nice once you figure it out!, That does have a lot of carbon on it, wondering if it was burning some bar oil

 

[JIMG]

I took this vintage group out today for an overdue clean up around our hay field perimeter.
That ugly 7-10 with the fresh P&C is the day's favorite.

 

[the 28inch mac man]

Hi, I'm new to this thread. I'm a mcculloch / all vintage saw lover. The yellow and black saws are the dearest to my heart. I have two 7-10s one 10-10 and two big 440s. One of my 7-10s is near perfect condition. I'm trying to buy a sp 81 that is MINT currently. I look foward to wasting a ton of time here in the future.

 

[Bigmac]

Hi, I'm new to this thread. I'm a mcculloch / all vintage saw lover. The yellow and black saws are the dearest to my heart. I have two 7-10s one 10-10 and two big 440s. One of my 7-10s is near perfect condition. I'm trying to buy a sp 81 that is MINT currently. I look foward to wasting a ton of time here in the future.

Welcome to the Mac madness!

 

[Squareground3691]

I took this vintage group out today for an overdue clean up around our hay field perimeter.
That ugly 7-10 with the fresh P&C is the day's favorite.

View attachment 426949

The 7-10 is a little hot rod ,

 

[heimannm]

Mark

 

[the 28inch mac man]

Welcome to the Mac madness!

Thanks man!

 

[the 28inch mac man]

The 7-10 is a little hot rod ,

I agree the 7-10 is a real beast of a saw. I used mine to cut a huge 40 inch ash stump the other day. I wish I had a picture of that stump! The tree had two 24 inch branches and a huge base. That 7-10 had no problem cutting that monster.

 

[JIMG]

Is that a 55 in your wagon with the black gas tank, Mark? I like mine quite a bit. I was wondering if those 10 series full wrap handle bars you had made would work on a 55 with a brake...

 

[JIMG]

I agree the 7-10 is a real beast of a saw. I used mine to cut a huge 40 inch ash stump the other day. I wish I had a picture of that stump! The tree had two 24 inch branches and a huge base. That 7-10 had no problem cutting that monster.

I was kind of surprised how not very far behind the 80 my 7-10 is.