McCulloch Chain Saws

[turtle561]

795 gap

is this too much of a ring gap on this 795 ? both gaps were in the exhaust area when i pulled the muff.did any of the macs have pinned rings ?
randy- is that top ring gap in your first photo pinned or free range like the 795?they look like thin rings too. are you going to re-ring or go with that gap ? were the thin rings normal ?
what is a good psi for these ?

 

[RandyMac]

I know zip, I just thrashed them. This is pretty much new to me.

 

[leeha]

is this too much of a ring gap on this 795 ? both gaps were in the exhaust area when i pulled the muff.did any of the macs have pinned rings ?
randy- is that top ring gap in your first photo pinned or free range like the 795?they look like thin rings too. are you going to re-ring or go with that gap ? were the thin rings normal ?
what is a good psi for these ?

That looks like a thick ring and the gap
is waaaay to much. The 790 and 795's
are not pinned. At least the ones i have
had apart. With that much wear, The piston
is probably wore out and the cylinder will need
to be bored. But can't be 100% without seeing
it.


Lee

 

[little possum]

Got to run the S44A today in some 20" or so slick bark hickory. That thing is awesome
Also put it in a 36" white oak. She just purred on and kept dragging chips.

 

[leeha]

Got to run the S44A today in some 20" or so slick bark hickory. That thing is awesome
Also put it in a 36" white oak. She just purred on and kept dragging chips.

Thanks, Now i have to get mine running.
I have heard there a fun saw to run with
nice power.


Lee

 

[little possum]

Lee, I wasnt sure on how it was going to run, but I was definitely suprised by the Rs it turned up and held in the wood. Just need to get some dogs so I can use the torque.

D-36 failed me today and wouldnt pick fuel up. It was just running not but a couple weeks ago

1-43 leaks oil, and the clutch is shot

 

[leeha]

Lee, I wasnt sure on how it was going to run, but I was definitely suprised by the Rs it turned up and held in the wood. Just need to get some dogs so I can use the torque.

D-36 failed me today and wouldnt pick fuel up. It was just running not but a couple weeks ago

1-43 leaks oil, and the clutch is shot

On the D36, What i do when a saw was running and then sat and can't get it to run.
Prime with mix down the carb, When the saw starts and revs up stuff a piece of thin hard cardboard right on the carb throat to act as a solid choke. It should help to pull the fuel through the carb.


Lee

 

[little possum]

Thanks Lee, Ill try that when I get to cleaning them up.

 

[turtle561]

Lee, that's what i was afraid of when i started cleaning the cooling fins and and saw that gap. using the DSP i never pulled against the real comp. seemed to run pretty good. especially after i converted to a tilly HL. i'll do a pressure test then decide if i'm up for a full tear down. at least it's clean now !

 

[a. palmer jr.]

is this too much of a ring gap on this 795 ? both gaps were in the exhaust area when i pulled the muff.did any of the macs have pinned rings ?
randy- is that top ring gap in your first photo pinned or free range like the 795?they look like thin rings too. are you going to re-ring or go with that gap ? were the thin rings normal ?
what is a good psi for these ?

I think there's a formula for so much end gap per inch of bore but I can't find the formula right now. I'll keep looking.

 

[Teddy.Scout]

A Mcculloch block labeled 1-71/1-81 with the 1-81 Xed out) that is equipped with a gear drive makes it? But the block also has 1-70/1-80 on the raised section in the middle were the block stamping is. Also the block is a 2-piece.
I am assuming it is a 1-85 since it has the air filter cover similar to a 125.

Thanks guys!

 

[Teddy.Scout]

Installing a bar stud on a 125?
Is there any creative ways with out opening it up?

Thanks

 

[Brian13]

I think there's a formula for so much end gap per inch of bore but I can't find the formula right now. I'll keep looking.

In a small engine repair book I have it says .004 per inch of piston diameter.

 

[CM76]

Installing a bar stud on a 125?
Is there any creative ways with out opening it up?

Thanks

Hi Matt,

You will need to remove the oiler housing assy from the saw to gain access to the bar studs and the single internal lock washer. This is an easy job - you will need to have the required spare gaskets on hand for the stuffer etc before undertaking the task though. Would be a good idea to replace the oiler rod seal at this time also.Depending on how the auto oiler is working - I would take the time to inspect it and carry out an overhaul at this time as well.

The 125's are a nice saw to work on, and have great performance to boot.

Enjoy!

 

[sachsmo]

McCulloch 10-10, 7-10 coil

I am working on a 7-10 and having problems getting it to run. It came to me with the small points eliminator module. My friend at work gave me the parts to convert it back to points ignition.

Question is: the coil has four taps, where does the lead from the condenser plug in? There was a grounding wire on one tap going to one of the coil mounting bolts, and of course the lead from the stop switch.

Can someone show me a picture or give me a brief explanation where the these leads go?

Thanks,

mo

 

[leeha]

In a small engine repair book I have it says .004 per inch of piston diameter.

I don't think that is correct.
That would mean in a Mac 123cc
saw you would have .009 thou
and thats way to much.


Lee

 

[thomas72]

Installing a bar stud on a 125?
Is there any creative ways with out opening it up?

Thanks

I would go ahead and take the oil tank off. I think only 7 bolts holds it on, and more than likely you probably have trash on the oil filter that has accumulated over the years.

 

[Brian13]

I don't think that is correct.
That would mean in a Mac 123cc
saw you would have .009 thou
and thats way to much.


Lee

It was a book on small engine repair my father gave me when I started rebuilding saws. It may not be accurate for chainsaw application. I went and did some looking around and found some pictures of instructions that came with some Mac rings and that suggested .003 to .0035 per inch of cylinder bore. What do you use for rule of thumb Lee?

 

[a. palmer jr.]

In a small engine repair book I have it says .004 per inch of piston diameter.

I think I'll write that down so I don't forget it again.

 

[leeha]

It was a book on small engine repair my father gave me when I started rebuilding saws. It may not be accurate for chainsaw application. I went and did some looking around and found some pictures of instructions that came with some Mac rings and that suggested .003 to .0035 per inch of cylinder bore. What do you use for rule of thumb Lee?

Are you talking piston clearance or ring end gap.


Lee