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McCulloch Mini and Small CC Chainsaw's

PogoInTheWoods

PogoInTheWoods

Don't forget about the alligators...
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Nah, man. It's all about persistence and determination. You'll get it sorted out.
Still getting my a$$ kicked by that MM25...today I'm breaking down and bending the metering lever down until level with the carb body. Still flooding with the new carb, MUST be the metering lever too high.
I took the liberty of moving this in order to respond over here. (Quote extracted from the Homelite thread...)

According to an early PM6 service manual, the metering lever height should be level with the carb body on carbs without a recessed metering chamber and lever. Carbs with a recessed metering chamber and lever should typically be adjusted level to .010 inch below the metering chamber floor, not with the carb body. Not sure if there were two versions of the Walbro carb or if the second reference may be for the ZAMA. Both are pretty standard reference points for each type of carb.

Lever Height.jpg
 
MacAttack

MacAttack

I love the smell of 2-stroke
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Excellent...saved to my phone!
As dumb as it sounds...I KNEW the metering lever was supposed to be close to even with the carb body. I actually managed to ruin a lever that was previously bent WAY too high by someone. I bent it back, and tried to fine tune, and the fork broke off. So...I was apprehensive to start bending a lever that came right out of another MDC. But obviously my flooding is due to the lever being too high, so I've bent it down almost even with the body, many the thickness of the lever above it, to try.
I found a thread on another chainsaw site where some guys had great luck adjusting Mini Macs with the metering lever set just below a metal ruler laid across the diaphragm gasket (instead of the body). That's where it is currently, I will try it and if it still floods I will lower it further. Not looking for a perfect running saw that will sit and idle for several minutes, just a usable setup. I'd prefer to not go too far and have to bend the lever back up again.
 
MacAttack

MacAttack

I love the smell of 2-stroke
Joined
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Messages
1,265
Location
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IT RUNS.... IT RUNS!! I CAN STOP TAKING APART THIS [email protected]#$#/?! MINI MAC!!!

Well first... After I lowered the metering lever and put it back together, I had a FEELING there was something unlucky about the ugly chain brake, so I installed the original "shred my face" plain clutch cover. It just looked.... better.

It took several pulls to prime up but NO flooding or stumbling on the high end. I will still need to do some fine-tuning but I think I finally have it corrected. Here's also a video of the little SOB making some racket. It did stall at the very end haha, I think it vapor-locked the carb a little, but then I got it running again and made some adjustments.

 

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Manic84

Manic84

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You've tamed the Mini Mac From Hell! Take a moment and rejoice as you piss off the neighbors with your victory! :p
But seriously, I am glad that you finally got it running MacAttack. You really showed great determination with this project. :cheers:
 
MacAttack

MacAttack

I love the smell of 2-stroke
Joined
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Messages
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You've tamed the Mini Mac From Hell! Take a moment and rejoice as you piss off the neighbors with your victory! :p
But seriously, I am glad that you finally got it running MacAttack. You really showed great determination with this project. :cheers:
Couldn't have done it without all your guys help! :cheers:
Back when it would run but couldn't pull on the top end, I am wondering if the old metering lever was actually too low and starving it for fuel. But also the points gap was too large. I am running the original coil which seems to be A-OK.
In any case, it seems to run good with the metering lever actually about .020" above the carb body, certainly not rich.
Now I can dive into my "Evil Dead" HOMELITE, then probably one of my project 10-10 Pros that needs to be revived, I have 2 of them in addition to my 2 running 10-10s.
And then like 3 basket case Mini Macs.
 
PogoInTheWoods

PogoInTheWoods

Don't forget about the alligators...
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Congratulations. That's some admirable determination right there. As is well documented, the will of many a lesser man has been thoroughly crushed by the mighty Mini-Mac. LOL

The stalling condition could be tank vent related. May be worth looking into if it continues. Vapor lock requires a fair amount of heat buildup in order to vaporize fuel, though it is a known issue with Mini-Macs. There's even a documented vapor lock recovery procedure in the MM manuals. Not sure if it's included in the PM6 manual, though.

Good luck with the Homie. Sawzilla is a good source for quality aftermarket top end parts. Some helpful guys over in the Homelite thread if you run into difficulty.

If it weren't fun...!
 
MacAttack

MacAttack

I love the smell of 2-stroke
Joined
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Messages
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Congratulations. That's some admirable determination right there. As is well documented, the will of many a lesser man has been thoroughly crushed by the mighty Mini-Mac. LOL

The stalling condition could be tank vent related. May be worth looking into if it continues. Vapor lock requires a fair amount of heat buildup in order to vaporize fuel, though it is a known issue with Mini-Macs. There's even a documented vapor lock recovery procedure in the MM manuals. Not sure if it's included in the PM6 manual, though.

Good luck with the Homie. Sawzilla is a good source for quality aftermarket top end parts. Some helpful guys over in the Homelite thread if you run into difficulty.

If it weren't fun...!
The tank vent definitely crossed my mind, I never really confirmed the tiny pinhole is actually clear. I actually cracked the tank cap open in case it was building a vacuum. If I run into it again I can easily pop the front cover off and check it out.
Yes...I refused to let the little bastard beat me, lol.
After it stalled the one time it ran perfect, it could have even been the old felt tank filter needing to soften up some more haha.
 
MacAttack

MacAttack

I love the smell of 2-stroke
Joined
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Spent some time cutting up some dead pine and some trees that fell in the field. After all the grief this MM25 is running real nice. Nice power, no stalling, starts easy. Auto oiler is pumping like crazy, I turned it down 1/4 turn.
I think it runs even better than my trusty old MM30.
Lesson learned...metering lever in the carb is a critical adjustment.
 

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Manic84

Manic84

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Let's leave it at....at least I have something to show for all the aggravation and time spent, haha.
How is the MM30 coming along?

That’s pretty much the creed us “Mini Mac Masochists” live by. :D
At the end of it, you fixed something most people would’ve given up on, or pulverized by now.

The 30 however… I have made no progress on it since the last update.
I had to stop everything. Hopefully I’ll be back after it in the next few weeks.
 
Manic84

Manic84

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Here is a little update since I finally had some time to get back to the 30.

I was able to free up the chain and clean it up a bit. It looks rough, but I have no real concerns about using it.
Everything is still original on the saw, even the bar and chain. Under all that rust, they all have the "McC" and "Mini" stamp on the bar and chain.
The bar was and is, the biggest pain in the ass by far. I'm not real satisfied with how it turned out, but I don’t want to get into that right now.

The carb still needs a bit of work, but it doesn’t seem too far gone. Amazingly, the original check valve was still intact. It was starting to winkle a bit, but I was able to pull it out without damaging it, so I think it’ll make for a cool souvenir for now.

The engine itself is great. The piston and cylinder are very acceptable and the original oil seals are still holding up.
I was able to test run the saw and it runs good. It needs some work still, but I’ll fine tune and tinker with it later.
I'm just happy that it runs.
 
MacAttack

MacAttack

I love the smell of 2-stroke
Joined
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Messages
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My next Mini Mac project is going to be my "super" mini. Will consist of a MM35 engine and housing and a 16" bar that came on a Mac 160s donor saw. I just ordered a carb kit, in the process of cleaning up the carb and getting all my parts sorted.
I am still trying to find the perfect pipe flange with a 1" inside diameter that I can use to hopefully rebuild some broken recoil pulleys. Best I can find so far are some bronze flange bushings with a 1" ID. I'm not sure they'd be ideal so still looking.
 
Woodslasher

Woodslasher

Make McCulloch Great Again!
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My next Mini Mac project is going to be my "super" mini. Will consist of a MM35 engine and housing and a 16" bar that came on a Mac 160s donor saw. I just ordered a carb kit, in the process of cleaning up the carb and getting all my parts sorted.
I am still trying to find the perfect pipe flange with a 1" inside diameter that I can use to hopefully rebuild some broken recoil pulleys. Best I can find so far are some bronze flange bushings with a 1" ID. I'm not sure they'd be ideal so still looking.
I have a spare metal pulley insert I'd send you if you need one.
 
Manic84

Manic84

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Well... I knew it was going to happen. The drum ratchet failed on the 30. (spinning in place)
When I have the time, I'll fix that before I can get to the bottom of a couple of issues that popped up with the saw.
 
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