McCulloch Mini and Small CC Chainsaw's

[farmhard]

I don't know what your hate for Mac's is all about. Remington's are my nemesis.

 

[piglosi]

Thanks Mark.

This Mac 120 lives again. My first one is a success. I left the Kotex in the fuel tank alone, and didn’t have a carb check valve, so crossed fingers it would be okay. Carb was a hot mess inside, cleaned with Pb blaster, carb clean, and some wires and air. Used a China kit which fit, but not close to the OEM quality. Reused main needle, China one was way long. MDC 15 carb. Runs and oils excellent. These saws are a pita to work on, but they are pretty tough and well made IMO. One has to want to fix em and have patience for sure. If it didn’t run, under the bench it would go.
Going over to my dads to retrieve an abandoned Mac 130. Going OEM/Walbro with this one

Thanks Mark.

 

[piglosi]

This Mac 120 lives again. My first one is a success. I left the Kotex in the fuel tank alone, and didn’t have a carb check valve, so crossed fingers it would be okay. Carb was a hot mess inside, cleaned with Pb blaster, carb clean, and some wires and air. Used a China kit which fit, but not close to the OEM quality. Reused main needle, China one was way long. MDC 15 carb. Runs and oils excellent. These saws are a pita to work on, but they are pretty tough and well made IMO. One has to want to fix em and have patience for sure. If it didn’t run, under the bench it would go.
Going over to my dads to retrieve an abandoned Mac 130. Going OEM/Walbro with this one

So the 130 is a Max 110. Clutch spring and linings broken and there is an old label on it saying leaks oil. Lol, a challenge! I’m gonna look around dads house tomorrow and see if there is another one kicking around and maybe I can make one good one. He had a few of these and never threw anything away.

 

[piglosi]

So the 130 is a Max 110. Clutch spring and linings broken and there is an old label on it saying leaks oil. Lol, a challenge! I’m gonna look around dads house tomorrow and see if there is another one kicking around and maybe I can make one good one. He had a few of these and never threw anything away.

Mac 110 not max

 

[piglosi]

This Mac 120 lives again. My first one is a success. I left the Kotex in the fuel tank alone, and didn’t have a carb check valve, so crossed fingers it would be okay. Carb was a hot mess inside, cleaned with Pb blaster, carb clean, and some wires and air. Used a China kit which fit, but not close to the OEM quality. Reused main needle, China one was way long. MDC 15 carb. Runs and oils excellent. These saws are a pita to work on, but they are pretty tough and well made IMO. One has to want to fix em and have patience for sure. If it didn’t run, under the bench it would go.
Going over to my dads to retrieve an abandoned Mac 130. Going OEM/Walbro with this one

Stihl 460 bucking dogg, custom!

 

[piglosi]

Stihl 460 bucking dogg, custom!View attachment 1116490

Gents I have a problem with a couple of the Eager Beavers with the cylinder filling with oil to the point they won’t pull start until it’s cleaned out. Is this a problem with that big O ring at the base of the oil pump or something else? Thanks in advance for the help. Pig

 

[dbm]

Before you put the automatic oil pump together, make sure it is correctly assembled and that it is working. There is one check valve in the top of the pump housing that is not accessible or serviceable so making sure not will avoid having to pull the front off the housing and removing the fuel/oil tank to change it later. The empty hole is the inlet, the one with the tube sticking out of it is the outlet to the bar. Put a drop or two of oil in the inlet hole and work the piston manually a few times, you should see the oil oozing out the discharge tube. The o-ring seal at the base of the automatic oil pump is a standard 020 o-ring, 1" O.D. and 7/8" I.D. They will cost $5.00 to $10.00 each if you buy them by the McCulloch part number 110653 off e-bay, or $0.50 to $1.00 or so each if you buy them from a bearing/hose shop, or $4.50 for 100 pieces from McMaster Carr + $6.00 for shipping.

View attachment 506360

The pump parts in order: pump body, adjuster sleeve, spring, piston assembly, and the o-ring seal.

View attachment 506370

The sleeve will only fit one way into the pump body and allow you to actually adjust the flow.

View attachment 506371

At this point I stopped taking photos, but reassembly is pretty straight forward. The biggest problem I have every time is getting the throttle rod reconnected. I find it is easier for me to remove the spring and take the throttle trigger and arm off the saw and get it connected, then reassemble the trigger to the housing and reconnect the spring. Your experiences may be different.

The little saw started right up and with a bit of adjustment would idle, rev, and oil as it should. I handed the saw back to the owner, we'll see if he can eventually come up with the $110 I had in parts.

Mark

My MM 30 is running great but no oil is getting to the bar, I disassembled everything and reassembled it, making sure that air was passing through all the tubes and hoses so I suspect it is the oil pump itself that is not moving oil. What is it that typically fails on the pump is it's simply the O-ring or are there other components that would cause it not to work properly? Just wondering if I should start changing parts or get an entirely new pump if I can find one.

 

[piglosi]

My MM 30 is running great but no oil is getting to the bar, I disassembled everything and reassembled it, making sure that air was passing through all the tubes and hoses so I suspect it is the oil pump itself that is not moving oil. What is it that typically fails on the pump is it's simply the O-ring or are there other components that would cause it not to work properly? Just wondering if I should start changing parts or get an entirely new pump if I can find one.

There is an adjustment screw for the pump that comes through the front cover. Make sure it is not turned all the way in. Back it out a few turns. I’m having oiler issues as well. There are NOS pumps on eBay if you are 45$ rich.

 

[piglosi]

This Mac 120 lives again. My first one is a success. I left the Kotex in the fuel tank alone, and didn’t have a carb check valve, so crossed fingers it would be okay. Carb was a hot mess inside, cleaned with Pb blaster, carb clean, and some wires and air. Used a China kit which fit, but not close to the OEM quality. Reused main needle, China one was way long. MDC 15 carb. Runs and oils excellent. These saws are a pita to work on, but they are pretty tough and well made IMO. One has to want to fix em and have patience for sure. If it didn’t run, under the bench it would go.
Going over to my dads to retrieve an abandoned Mac 130. Going OEM/Walbro with this one

The Max 120 is a beast in the wood once final tuned. Cut about 4 tanks gas, 10 on oil. Hindsight, I wish I had heeded Mark’s advice and waited on a check valve for the carb. I think mine is toast. Anyone have any kits to sell? Should I pull the brass plug or work a new disc in made from diaphragm material? I’ve never replaced a check valve and been running Macs and Homelites for awhile. Lucky. Any help greatly appreciated

 

[heimannm]

No oil at all on the MM could simply be a stuck piston, or a stuck check valve. You will have to remove the front cover and pull the fuel/oil tank off to get at the oiler. Slide the bail off and remove the pump to check the piston and the check valve. I suspect you would find more details in the back pages of this thread.

The Walbro 86-523 check valve kit will work on the MDC but you have to find a 7/16" Welch plug for the MDC vs. the 5/16" that comes with the kit for the SDC carburetors.

Mark

 

[piglosi]

No oil at all on the MM could simply be a stuck piston, or a stuck check valve. You will have to remove the front cover and pull the fuel/oil tank off to get at the oiler. Slide the bail off and remove the pump to check the piston and the check valve. I suspect you would find more details in the back pages of this thread.

The Walbro 86-523 check valve kit will work on the MDC but you have to find a 7/16" Welch plug for the MDC vs. the 5/16" that comes with the kit for the SDC carburetors.

Mark

Thanks for the info Mark. That helps, I got Welch plugs with the MDC carb kit, I’ll measure and see if there’s a 7/16. I used MacAttacks fuel line suck blow truck removing the high speed needle and there is no resistance.

 

[piglosi]

Stihl 460 bucking dogg, custom!View attachment 1116490

This is a humble fabrication but I traced a template and the next one will be a closer match to the case. The dog works well and you can really lever the saw into firewood.

 

[piglosi]

Thanks for the info Mark. That helps, I got Welch plugs with the MDC carb kit, I’ll measure and see if there’s a 7/16. I used MacAttacks fuel line suck blow truck removing the high speed needle and there is no resistance.

I have noticed on 2 mini Macs I’ve disassembled the oil pump clamp is not clamped into the cast retaining nub on the crankcase. One side is, other outside the nub. Is it proper to only clip one side in? Would that affect sealing of the pump o ring? Thanks!

 

[heimannm]

They can be very difficult to get clamped in place properly. As tight as they fit, I would not be over concerned about the o-ring leaking even it the bail was not fully snapped in place. That said, I always make the effort to get the bail properly seated on both ends.

Mark

 

[dbm]

There is an adjustment screw for the pump that comes through the front cover. Make sure it is not turned all the way in. Back it out a few turns. I’m having oiler issues as well. There are NOS pumps on eBay if you are 45$ richthanks - I

There is an adjustment screw for the pump that comes through the front cover. Make sure it is not turned all the way in. Back it out a few turns. I’m having oiler issues as well. There are NOS pumps on eBay if you are 45$ rich.

yup - did that first .. i completely disassembled the oiler (multiple times), blew air through all the hoses and ports, but no luck getting it to pump - nor let oil through once its reassembled. I read there is a non-serviceable check valve in the housing, so maybe that is the culprit. I may have to drop the $40 .. the saw is running great (And now its all clean and shiny after multiple assemble/dis-assembles)

 

[dbm]

I don't know how similar / different an Eager Beaver oil pump is to a Mini Mac oil pump, but assuming that phenolic disc thing is operating from the crankcase pulses, there is that tiny check-ball gizmo that needs to work in order to pump oil.
Mark is an expert on those things, if the little check ball gets stuck you CAN possibly get it freed up.
More so than the O-ring, I'd guess the check ball is stuck, assuming the pump is assembled correctly.
I just thank God when they work, haha

I have this problem - how do you get the check ball unstuck ? I

 

[heimannm]

Usually you can free them by spraying carburetor cleaner or brake cleaner down the hole where the piston goes. Spray, install the piston and pump it manually, then put some oil in the inlet hole and work the piston manually to see if it goes down the inlet and out the outlet. You can also use your pressure tester with a piece of tubing slipping over the steel sleeve in the oil pump, it should pass pressure to the outlet, but hole a vacuum if the check ball is working.

They are reported to be non-serviceable but you can pull the steel sleeve out and check, clean, replace the parts as needed, just be sure to measure how far the steel sleeve is pressed into the body of the pump before you take it apart so you can get it back to the proper position.

L-R Pump body, plastic sleeve, spring, piston



L-R Pump body, check spring, check ball, steel sleeve, plastic sleeve, spring, piston



You should be able to see the hole/groove in the bottom of the inlet when the steel sleeve is pressed in to the proper depth.



Mark

 

[piglosi]

Mark,
I have a Zama carb and kit to rebuild. Looking at the IPL, it appears there is a check valve in these as well. How often do you replace them or find them bad?

 

[piglosi]

Mark,
I have a Zama carb and kit to rebuild. Looking at the IPL, it appears there is a check valve in these as well. How often do you replace them or find them bad?

Also, do you seal the Welch plug with anything like nail polish? Over read some do and some don’t.

 

[heimannm]

I think the Zama uses a screen, similar to the sintered metal "capillary seal" used in some of the flat back carburetors in place of a high speed check valve. I have never had an issue with a Zama carburetor that gaskets & diaphragms did not fix.

I do not use anything on the Welch plugs, just make sure they are properly seated using a suitable size punch.

Mark