McCulloch Chain Saws

[2broke2ride]

So I pulled down the SP81 today. The I take boot was I stalled wrong. The spring was between the boot and the carb box and pinched in the boot instead of being between the boot and the engine plate.
I have plenty of cleaning to do. What should I be looking g at for the inop manual oiler? I've never had one not work and the auto oiler wasnt pumping much either. Also, the kill switch is inop. I assume there should be a ground strap somewhere to connect the handle to the engine, where should that be located? I found no such thing on disassembly.

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[vinnywv]

To test the ground of your stop switch, use a multimeter and set it to resistence or ohms. Then find a bare spot on both the tank and the bottom half of the saw. You should get a dead ground with the switch off. If you dont have a multimeter, take a piece of wire thats bare on both ends. Start the saw.then turn off the switch. Your saw as described should still be running, now touch the bare ends from the tank half to a bare spot on the engine half. Your saw should stop. The ground strap is located on the front av. From the oil tank to the fuel tank. The av holds the kill switch out. Typically it is one eyelet on the oil tank av stud, the other strap eyelet on one of the 2 - 1/4" bolts that the av mounts to on the front underside of the fuel tank.

 

[vinnywv]

The oiler could be a few things, typically i find them dirty. Ill take the pump out of the oil tank and take it apart and clean it. Theres a disc in there, hopefully its not broken, a spring, a spacer and a little piece of felt. Ill take them all out and clean it really good and put it back together and test it. Oil goes in one small hole and out the other. There should not be oil inside the pump. Ill spray wd40 or kroil into one of the small holes and with the pump in hand using a finger ill push the disc up and down in the pump. The spray of choice should eventually ooze out the hole. Then ill put it back together in the tank and try again.
Another thing to try for the manual pump is to place your finger tip over the outlet where it would oil the bar. Stop it up with your finger and manually pump it. Sometimes the little check disc gets hung up. Thats worked for me too on some.

Also make sure the oil line is in good shape. And not plugged on the screen. They are not fun to replace so dont pull it out of the tank until you have no other option. Im sure others will have some ideas too but thats a couple to get you busy.

 

[PogoInTheWoods]

What should I be looking at...

This is pre E but should cover your prefix.

 

[Maintenance supervisor]

Looks decent inside. The ole MAC was chugging.

It literally ran out of gas as I finished one cut. So it was a full tank of fuel for 10 feet and 11 inches of this log

Spalted wood is always great, what are your plans with it?
Thirsty McCulloch, horse power has to come from somewhere.

 

[joeymt33]

Spalted wood is always great, what are your plans with it?
Thirsty McCulloch, horse power has to come from somewhere.

No plans right now, both trees were dead and in the way of another project so they will be cut up into bigger pieces and put in out of the weather for now.

 

[Todd Loosli]

Got the rings for the 73 today and I machined the piston for them. Just finished putting the piston back on the rod and installing the cylinder. I am making progress.

 

[2broke2ride]

To test the ground of your stop switch, use a multimeter and set it to resistence or ohms. Then find a bare spot on both the tank and the bottom half of the saw. You should get a dead ground with the switch off. If you dont have a multimeter, take a piece of wire thats bare on both ends. Start the saw.then turn off the switch. Your saw as described should still be running, now touch the bare ends from the tank half to a bare spot on the engine half. Your saw should stop. The ground strap is located on the front av. From the oil tank to the fuel tank. The av holds the kill switch out. Typically it is one eyelet on the oil tank av stud, the other strap eyelet on one of the 2 - 1/4" bolts that the av mounts to on the front underside of the fuel tank.

This is what I found for a "ground strap" dont think it will do much like that lol.

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[Maintenance supervisor]

This is what I found for a "ground strap" dont think it will do much like that lol.

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Yup that strap is totally grounded!

 

[mogulmasher]

Ya that strap isn't doing much, lol.

 

[mogulmasher]

Was hoping to try out the new to me 10-10s today. Even though it runs well I found out why saws are usually shelfed....something is wrong with it. Oiler isn't working. Nothing comes out when running. At first manual oiler has no resistance, after pumping some and cracking open cap on tank it started building pressure. However oil wasn't coming out hole, it is pumping out somewhere else on the motor and squirting out from under the saw. I can't tell where, it's just coming out around lower cover by where front handle mount is. Any clue what's going on here?

 

[joeymt33]

Was hoping to try out the new to me 10-10s today. Even though it runs well I found out why saws are usually shelfed....something is wrong with it. Oiler isn't working. Nothing comes out when running. At first manual oiler has no resistance, after pumping some and cracking open cap on tank it started building pressure. However oil wasn't coming out hole, it is pumping out somewhere else on the motor and squirting out from under the saw. I can't tell where, it's just coming out around lower cover by where front handle mount is. Any clue what's going on here?

Probably leaking from the gasket area between the manual pump and the oil tank. Anytime I’ve had a blockage that’s where they leak.

It sucks because you’ve got to separate the tank from the motor to access it

 

[mogulmasher]

Probably leaking from the gasket area between the manual pump and the oil tank. Anytime I’ve had a blockage that’s where they leak.

It sucks because you’ve got to separate the tank from the motor to access it

So I'm assuming once it leaks there even if you clear blockage the damage has been done to that gasket?

 

[vinnywv]

So I'm assuming once it leaks there even if you clear blockage the damage has been done to that gasket?

Those gaskets are pretty tough, the manual pump is held on with 2 sceews. Id bet one or both is loose or missing. The one closest the fill cap has a nut on it accesed from inside the oil tank cover. The other is a little longer with no nut.

 

[joeymt33]

So I'm assuming once it leaks there even if you clear blockage the damage has been done to that gasket?

I don’t think I’ve had to change the gasket. It’s been so long now I can’t remember what was plugged. It was a probably plugged in circuit from the manual oiler over to the bar.

 

[MacAttack]

Hey Guys,

I could use some input from anyone familiar with Mac point ignitions. So...the coil in the SP40 (Super Pro 40) i picked up cheap is bad, tests no resistance in the secondary winding. Argh.

I have another coil on a Mini Mac 35 engine that i could not get to spark, but I was never able to pinpoint why for sure, because the coil SEEMED to be ok. Below is how i tested the MM35 coil. If i did this right, I'm seeing 1.8ohm on the primary winding and 7.38K on the secondary. I could not find specs anywhere. Could anyone tell me if this coil appears good? The coils appear to be interchangable.

On top of that, it feels like the crank bearings might need replacing on the SP40 even though the saw does not appear to have a lot of use. And the carb on my MM25 is leaking gas and flooding the engine. Getting kinda bummed on these little Macs...

 

[edju1958]

Was hoping to try out the new to me 10-10s today. Even though it runs well I found out why saws are usually shelfed....something is wrong with it. Oiler isn't working. Nothing comes out when running. At first manual oiler has no resistance, after pumping some and cracking open cap on tank it started building pressure. However oil wasn't coming out hole, it is pumping out somewhere else on the motor and squirting out from under the saw. I can't tell where, it's just coming out around lower cover by where front handle mount is. Any clue what's going on here?

If the gasket checks out good & the screws are there & they're tight,you might have a hair line crack.
Ed

 

[MacAttack]

Well i swapped the coil, nada, zip, nothing.
I feel like i have 2 junk coils, but if anyone knew the factory specs i would genuinely appreciate it.

 

[Maintenance supervisor]

Boy I sure wish they still made. 404 in .050 guage, the loop of old stihl #5 I found really cuts nice in a mill!
The old 700 flew through some 10-12" cedar ,but being almost 90° in the sun made the fuel boil a couple times. Took a few breaks in between cuts.
That short clutch cover I restored sure was nice to fit in the mill.

 

[mogulmasher]

If the gasket checks out good & the screws are there & they're tight,you might have a hair line crack.
Ed

Well this will do it. The disc in the pump wasn't attached to the pin. Not sure where the pieces could have gone. Scratches by the pump spring clip lead me to believe someone else has been in here before. Threw a good used pump in it. I'll put it back together tonight.