McCulloch Chain Saws

[Rocker59]

Are you sure? In all the videos of 2-10s I have seen, none have DSP.
In photo searches I see some labelled 2-10A which have what I guess is a DSP switch on the top? Otherwise I see 2-10s without it.

From what I have gathered, when the 2-10 first came out it was a 1-10 with an automatic oiler. 2-10A was marketing. The 3-10 in it’s two forms was also around this time. Then the Super 2-10 arrived. It had the “Super” tank/air filter combo (later “Pro Mac”), the DSP from the 3-10, and an SDC carb. There was also the SDC upgrade kit with the tank that was offered as an after sale upgrade. This made a 3-10 DSP into a super 2-10 and a 5-10 into a 6-10. To confuse things even further, there are IPLs that show a 2-10 with the DSP and there was also one run of Super 2-10s with the later push button decomp. Then there was the 10-10, Super 10-10 and Super 10-10E….

 

[Rocker59]

Forgot to mention the Tillotson HS43, with/without locking push button choke that appears I don’t know if it was a factory authorized upgrade or not. The ones I’ve seen came with an aluminum carb insulator. The 1970 McCulloch Carb Guide shows them being on the Mac 1-10 and Super 10-10A from the factory.

 

[Syncop8r]

Forgot to mention the Tillotson HS43, with/without locking push button choke that appears I don’t know if it was a factory authorized upgrade or not. The ones I’ve seen came with an aluminum carb insulator. The 1970 McCulloch Carb Guide shows them being on the Mac 1-10 and Super 10-10A from the factory.

I think that's what I've got.
I assumed it was a mod.

 

[sawfun]

Anyone interested in working on a 1-72? Low compression 90# piston and cylinder look good. It's just out of my skill level right now but would like to get it going

The rings likely took a set and need to be replaced. Working on those large frame Macs is quite a bit different than conventional saw engines. It isn't harder just different to work on. You do have to take the complete saw apart, but it's pretty easy.

 

[drumbum]

Seen this ?

 

[Jethro 2t sniffer]

850 time as I need a saw and 81 is down.

Been yonks since last run. Fired up n runs good

Oiler pumps perfectly in my hand.

When running it auto oils at idle. When open throttle it does not. I've tried different pumps n same result. The manual pump loses prime. Takes 3 or 4 pumps before it primes up and after 5 or 10 seconds prime is gone again.

It's doing in my head and was why it got parked

 

[edju1958]

View attachment 1108551View attachment 1108552
850 time as I need a saw and 81 is down.

Been yonks since last run. Fired up n runs good

Oiler pumps perfectly in my hand.

When running it auto oils at idle. When open throttle it does not. I've tried different pumps n same result. The manual pump loses prime. Takes 3 or 4 pumps before it primes up and after 5 or 10 seconds prime is gone again.

It's doing in my head and was why it got parked

Wondering if you have a cracked oil line that feeds both pumps? (the line in the tank)

 

[Maintenance supervisor]

View attachment 1108551View attachment 1108552
850 time as I need a saw and 81 is down.

Been yonks since last run. Fired up n runs good

Oiler pumps perfectly in my hand.

When running it auto oils at idle. When open throttle it does not. I've tried different pumps n same result. The manual pump loses prime. Takes 3 or 4 pumps before it primes up and after 5 or 10 seconds prime is gone again.

It's doing in my head and was why it got parked

Could there be a booger in the impulse port behind the pump?

 

[Jethro 2t sniffer]

Wondering if you have a cracked oil line that feeds both pumps? (the line in the tank)

Could be. It looks fine but could be

Could there be a booger in the impulse port behind the pump?

Also possible. I'll check.

I'm pulling the tank off n try a different manual pump n see if that helps.

Huge compression this thing. Really deserves to be run lots

 

[Jethro 2t sniffer]

I undid everything the boot won't come off but before it did I managed to get the pump out. It seemed to be half in bits already and the cap off the back is full of saw dust.

The saw seems to slide back n forth underneath the tank quite a bit. Not sure if I'm missing something on the front lower mount and wondering if it had something to do with the oiler falling to bits

I'm green as on the AV saws and never really had an issue with them to warrant pulling it down.

Is it the same pump of the regular rigid 10 series? I have plenty lying around

Pretty sure it's got something to do with my issues. The auto pump is working well. The hose is not split the impulse port is clear

 

[Maintenance supervisor]

View attachment 1108608View attachment 1108609
I undid everything the boot won't come off but before it did I managed to get the pump out. It seemed to be half in bits already and the cap off the back is full of saw dust.

The saw seems to slide back n forth underneath the tank quite a bit. Not sure if I'm missing something on the front lower mount and wondering if it had something to do with the oiler falling to bits

I'm green as on the AV saws and never really had an issue with them to warrant pulling it down.

Is it the same pump of the regular rigid 10 series? I have plenty lying around

Pretty sure it's got something to do with my issues. The auto pump is working well. The hose is not split the impulse port is clear

Wow that sucked in alot of sawdust! That definitely would have affected the little disk check valve.
I believe that those are the same pump as the othe 10 series.

 

[knightmax]

Yes same as the rest of the 10 series.

Getting that manual oiler off without taking the tank off is damn near a miracle. I have never attempted that honestly. that is the pump for the manual oiler. the auto oiler is all contained inside the front of the crankcase. Like MS already stated checking the impulse port in the oil reservoir behind auto oiler is something worth trying. My other thought and sadly very possible is that there is a hairline crack in the front of the crankcase/oil reservoir. This would create the exact issues you are having. I hope I am wrong. Mark may be able to add more insight also. The auto oiler and the manual oiler work independently from each other. The fact they are both losing prime is why I suspect there may be a crack.


Once you get her oiling right you will run the PM850 as much as the SP81. To this day if I had to pick one over the other I am not sure I could.


EDIT: AFTERTHOUGHT... If the gasket under the manual oil pump was cracked it might also cause you issue.

Now back to my coffee lol

 

[Jethro 2t sniffer]

That end cap with the saw dust was halfway up the oiler rod . And the plunger was hanging out the back a little. I suspect it was losing prime out there. Odd that it was auto oiling at idle but it was literally years ago now and may have changed. I didn't bother to try it this time.

Just seems like the oil was running back down the hose with an air leak at the manual pump and the auto can't pump if the oil isn't there to pump

Hopefully not a crack.

I did used to run it but got sick of oiling issues.

The 850 is heavier than the 81. Might put a short cover on if I get it sorted

 

[edju1958]

Jethro,when you pulled the manual oil pump out from under the tank,did you manage to save the small check valve disc?

 

[rwoods]

...
The 850 is heavier than the 81. Might put a short cover on if I get it sorted

Me thinks - all that aluminum instead of magnesium adds up quick. Ron

 

[rwoods]

The saw seems to slide back n forth underneath the tank quite a bit. Not sure if I'm missing something on the front lower mount and wondering if it had something to do with the oiler falling to bits

Make sure the bottom of the a/v mount is tight with the tank and no leakage there. Ron

 

[Jethro 2t sniffer]

Jethro,when you pulled the manual oil pump out from under the tank,did you manage to save the small check valve disc?

Yes

Me thinks - all that aluminum instead of magnesium adds up quick. Ron

Definitely yes

Make sure the bottom of the a/v mount is tight with the tank and no leakage there. Ron

Thank you

 

[Jethro 2t sniffer]

Any preference?

 

[Squareground3691]

New Shirt , Lol

 

[Maintenance supervisor]

Any preference? View attachment 1108717

Screws holding the oil pump on..