Nice job on those Mini Macs, they look great! 
And thank you for that picture. It really means a lot. Once again, thank you.
And thank you for that picture. It really means a lot. Once again, thank you.
McCulloch Mini and Small CC Chainsaw's
- Thread starter Overtrained
- Start date
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MacAttack- I have the MM AF cover with a screw, and the rubber plug for the auto sharp opening.
Mark
Mark
I've actually not pulled that particular carb yet. That saw is still a project in progress -- a successful one so far I might add. The detonation/pinging sound stopped on its own and may well have been the clutch drum as Mark suggested. The chain was just a hair rusty and I pre-oiled it hoping the minor amount of rust involved would work itself out. I did initially notice the chain advancing and stopping at idle (very minimally) like tension was building and being released which obviously could have had the clutch doing some weird things until the chain loosened up a bit. I've not noticed the problem the last couple of times I've played around with the tuning..., which doesn't quite dial in yet. A kit is in its future. It still fires right up and runs though, so I at least seem to have rescued some pretty nasty points.
All the above ramble aside, I did have another MDC handy to check for the mystery screen and wasn't able to see one.
But all this time I was under the impression the location being described was beneath the needle seat of the high jet, not under the metering needle seat. I'll check again today and see if it has one there.
Alaskan Stihl
ArboristSite Operative
Age Old Fuel Question:
So, as my chainsaw collection continues to expand…so does the Make & Models. I have a couple of Stihl MS290’s, couple of Stihl 031AV’s and a MS180c. Obviously, I use the Stihl Synthetic 2-Stroke Oil to mix 50:1 (regular gasoline).
Now, I also have added to the collection: McCulloch Super 797, McCulloch PM610, McCulloch 10-10, McCulloch Wildcat and McCulloch 110. Not to mention a Craftsman Mid-size saw….along with a Homelite EZ.
What would be nice to know is if I could continue to use the Stihl Synthetic blend mix (50:1) on all the saws and not worry about anything seizing up….because I have also read various opinions which states NOT to use 50:1 Mix for the older McCulloch Chainsaws.
Since I have already used it in all of various running McCulloch’s etc, I tend to believe everything should be fine (I guess if they seize up while putting them through a heavier load…then I will know for sure though…?)
Question: Am I safe to continue to run that blend (Stihl Synthetic 50:1) on all the saws…or should I mix a richer blend for the older McCulloch’s?
So, as my chainsaw collection continues to expand…so does the Make & Models. I have a couple of Stihl MS290’s, couple of Stihl 031AV’s and a MS180c. Obviously, I use the Stihl Synthetic 2-Stroke Oil to mix 50:1 (regular gasoline).
Now, I also have added to the collection: McCulloch Super 797, McCulloch PM610, McCulloch 10-10, McCulloch Wildcat and McCulloch 110. Not to mention a Craftsman Mid-size saw….along with a Homelite EZ.
What would be nice to know is if I could continue to use the Stihl Synthetic blend mix (50:1) on all the saws and not worry about anything seizing up….because I have also read various opinions which states NOT to use 50:1 Mix for the older McCulloch Chainsaws.
Since I have already used it in all of various running McCulloch’s etc, I tend to believe everything should be fine (I guess if they seize up while putting them through a heavier load…then I will know for sure though…?)
Question: Am I safe to continue to run that blend (Stihl Synthetic 50:1) on all the saws…or should I mix a richer blend for the older McCulloch’s?
More like ANOTHER OIL THREAD!!! warning. LOL
50:1 with good synthetic oil (HP Ultra is one, IMHO) will work in all those saws. I personally use HP Ultra in all my saws from early vintage to mildly ported work saws at 40:1 for a little more bottom end lubrication. I've seen plenty of bearing damage from cheap (or too little) mix oil at 50:1 in saws that still have good top ends..., particularly in the modern high rpm (and high heat) saws. You could damned near use diesel as mix oil in the older saws and they'd probably still run.
To each their own, of course. To answer your main question; I'm going with a 'yes', though I personally prefer a little more insurance at 40:1.
I just run everything 40:1, I've found no benefit in running 50:1 in terms of clean running or plug fouling.
Modern oil is much better, especially the FD rated oils, I use Echo Powerblend.
Modern oil is much better, especially the FD rated oils, I use Echo Powerblend.
There's something I just like about a mineral/synthetic blend oil, probably all in my head, but I feel like it gives it some additional corrosion-prevention. I've had great luck with the Echo oil so far after about 5 years of switching everything to it.
I can't remember where I got reconmended the Echo oil to start but I've never had any issues that I'm aware of. When I get stuck on something its hard to pry me from it. Been using BelRay in my 78cr250 and it runs as good now as it did 25 years ago, so I just keep it around. Pennsoil in my vehicles....same thing. i'm sure there's better but I've never had a problem and I seem to get good longevity with the machinery. That 's just me, not for everyone.
Very interesting diagram, there must have been a few different designs of MDC carbs regarding the adjustment needles.
It's no wonder they can be tricky to get the idle consistent when you see how the idle circuit works.
It's no wonder they can be tricky to get the idle consistent when you see how the idle circuit works.
Tore a MacCat apart today. Felt like it had tremendous compression. Pulled the plug, pulled the rope and blew bar oil everywhere. Fuel tank was full of bar oil. I have always found these saws interesting because the oil pump function by vibration. Someone has also broken the pump.
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The automatic oil pump works off the crankcase impulse signal just like the 10 Series, Mini Mac, and large frame saws.
Mark
Mark
I can see that now but it also has a metal rod into the top of the pump. When you push that rod it pumps oil. It is bolted to the case and I assume it works from vibration.
That metal rod should be operated via a fiber disc attached to one end that oscillates from the crankcase pulses. I've taken several apart on the small MACs.
The finished product...ugly, screwed and glued. I used a 2-part epoxy to attach the repaired pawl assembly to the sheave, along with some tiny screws. I need to find some more #4 or #2 screws online, the hardware stores only seem to carry #6.
Will be installed in the Mini Mac 25 today. I have at least one more broken pulley I can fix this way, in which the plastic cup has been completely destroyed.
Will be installed in the Mini Mac 25 today. I have at least one more broken pulley I can fix this way, in which the plastic cup has been completely destroyed.
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Looks like a strong design. Nice work! All that fab work should pay off and give a long life to that repaired pulley. Thanks for posting your progress on it. I've enjoyed watching your design work.
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Thank you! It's not the prettiest repair job, but it's definitely strong and functional. Seems to work perfect!
