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McCulloch Mini and Small CC Chainsaw's

Manic84

Manic84

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Nov 20, 2019
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562
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This came in the mail from a leather working supplier haha, nice US made 7/32 hollow punch that I will hopefully be able to use to make some check valves!

I also have one Walbro check valve kit and a 10 pack of Stens 7/16 Welch plugs coming. I will use the Walbro kit as a reference for how the valve should look, and I have one Walbro welch plug as a guide to file down the Stens plugs to the right thickness. The Walbro check valve kits are almost $10 a piece now! That's as much as I paid for the punch. I have plenty of unused carb diaphragms to sacrifice to make check valves. Thanks again to Manic84 for all the ideas!

View attachment 868946 View attachment 868947

I'm a bit late to the party but... Awesome! ($10 for each kit? That's nuts!)
To file the plugs down I used a raker file, it was perfect for the job. It doesn't have to be exact, just close enough to the original.
Let us know how it works out. :)
 
MacAttack

MacAttack

I love the smell of 2-stroke
Joined
Nov 15, 2019
Messages
974
Location
Western NY
I'm a bit late to the party but... Awesome! ($10 for each kit? That's nuts!)
To file the plugs down I used a raker file, it was perfect for the job. It doesn't have to be exact, just close enough to the original.
Let us know how it works out. :)
Definitely will! The next saw going onto my workbench will be the Mini Mac 25 with the carb issue, I will be replacing the check valve and will try making one. I have high hopes for the hollow punch, I will try to get some good photos of the end results. It's absolutely insane what they are charging for the check valve kits, that don't even have the right welch plug for the MDC carb!
If it fixes the MM25 I will be thrilled. It's a bummer the saw is sooooo clean but just runs awful.
 
Mnmacguy

Mnmacguy

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46
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First small mac. Mac 110.
Looks like it's in great condition. Just a bit grimy. A good project saw.

If you haven't checked for spark yet maybe have a look before you start disassembling it so you know if the points or coil need attention.

Sent from my SM-S367VL using Tapatalk
 
Brushswamper523

Brushswamper523

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Dec 26, 2020
Messages
39
Location
California
Looks like it's in great condition. Just a bit grimy. A good project saw.

If you haven't checked for spark yet maybe have a look before you start disassembling it so you know if the points or coil need attention.

Sent from my SM-S367VL using Tapatalk
Thanks. I will check that out first for sure.
 
Brushswamper523

Brushswamper523

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Messages
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Does that come off i am having a really hard time getting this motor out of the case. I believe that is holding it up.. Thanks in advance.
 

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MacAttack

MacAttack

I love the smell of 2-stroke
Joined
Nov 15, 2019
Messages
974
Location
Western NY
A good tip (probably in those videos) is stick the throttle link on the flywheel magnet. That might be more for reassembly... I can't remember.
Id say mostly assembly, that little throttle link is a PITA. That and fishing the plug wire through the rear opening, and getting the fuel outlet fitting to line up are the toughest parts for me at least.
 
Brushswamper523

Brushswamper523

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Messages
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Huh, my mini Macs dont have that collar over the idle screw, does it slip up and and off?
I tried to slip it off wouldn't come off I had to remove the idle screw the carb needs to be rebuilt good old left fuel in the machine. Lol. And have to order carb kit. So here come another week waiting for the kit
 
Manic84

Manic84

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Joined
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Messages
562
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Does that come off i am having a really hard time getting this motor out of the case. I believe that is holding it up.. Thanks in advance.

Huh, my mini Macs dont have that collar over the idle screw, does it slip up and and off?

I tried to slip it off wouldn't come off I had to remove the idle screw the carb needs to be rebuilt good old left fuel in the machine. Lol. And have to order carb kit. So here come another week waiting for the kit

The later Minis had this "collar" on the carb, it's called the throttle latch button and it's part of the idle speed screw.
It's just a bad idea for a throttle lock, it's very hit and miss. When you take it out, be aware of the spring that is on the screw. It should come with the whole thing when you take it out, but it can fall off. (if it does, good luck finding it)

Another thing to look for that sometimes happens when the saw runs, is the screw can back itself out and the saw will stall.
A simple way to check if this might happen, is to just wiggle the screw back an forth in the carb. If it has an excessive amount play, you need to fix it.

I have a 110 that had that problem. The way I "fixed" it, was I wrapped a small piece of teflon tape around the threads of the screw.
With the slack taken up and the pressure of the *spring keeping it in place, it stopped stalling at idle.

* I lost the original spring on mine and replaced it with one from a pen.
 
Brushswamper523

Brushswamper523

ArboristSite Lurker
Joined
Dec 26, 2020
Messages
39
Location
California
The later Minis had this "collar" on the carb, it's called the throttle latch button and it's part of the idle speed screw.
It's just a bad idea for a throttle lock, it's very hit and miss. When you take it out, be aware of the spring that is on the screw. It should come with the whole thing when you take it out, but it can fall off. (if it does, good luck finding it)

Another thing to look for that sometimes happens when the saw runs, is the screw can back itself out and the saw will stall.
A simple way to check if this might happen, is to just wiggle the screw back an forth in the carb. If it has an excessive amount play, you need to fix it.

I have a 110 that had that problem. The way I "fixed" it, was I wrapped a small piece of teflon tape around the threads of the screw.
With the slack taken up and the pressure of the *spring keeping it in place, it stopped stalling at idle.

* I lost the original spring on mine and replaced it with one from a pen.
Copy that it seems tight in the carb so hopefully I won't have any issues. Then comes the tuning which I need much practice at does it fallow the 1 turn out on each theory or is there something different
 
MacAttack

MacAttack

I love the smell of 2-stroke
Joined
Nov 15, 2019
Messages
974
Location
Western NY
Copy that it seems tight in the carb so hopefully I won't have any issues. Then comes the tuning which I need much practice at does it fallow the 1 turn out on each theory or is there something different
1 turn out on both needles is a good starting point, I actually have an original mini Mac 6 owner's manual on my workbench with the carb tuning procedure. I think it suggests 3/4 turn out on the low speed idle, but I just start both at 1 turn.
While you have it apart, Id recommend taking apart the automatic oilier to check the movement and condition of the pump rod and fiber disc that seals im the pump body, and to clean it out good with some brake kleen. Also clean the engine fins where sawdust packs in them.
 
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