McCulloch Mini and Small CC Chainsaw's

[Mnmacguy]

I am in the process of moving everything from my home shop/garage to my new building. I have moved most of the NOS parts that were in small parts bins, etc. so today I decided to get the rest of the small saw stuff out of the attic.

View attachment 882377

This does not include the parts saws still in the attic, between MM, PM6, and 300 Series saws there may be 20-25 units left...and a few more boxes with parts. I really didn't realize how much stuff there is up there.

Mark

That's a nice hoard of parts there! With some of the crazy prices I've seen on Ebay lately I'd say you invested your money well.

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[drumbum]

I recently acquired a 3516 with another saw I wanted. Fuel lines and bulb rotted, so tor it down and cleaned it up (regrets). Lines are hooked up properly. Saw will run without the carb installed, so coil good, but floods with carb installed.

Had the carb apart and put a fresh pump diaphram and metering sheet and gaskets. Still floods. Needle looks good as well as the seat.

I would have sworn no one was in this saw previously...but...

Never had this kind of trouble with a carb.

Any known issues with these Walbro WT 438's?

 

[heimannm]

I had one (3200, basically the same saw) that would start and run for a few minutes then flood. I ended up replacing the carburetor when the original would not hold pressure even after replacing the diaphragms and lapping the needle.. Try to pressure test your carburetor (pressurize the fuel inlet to around 9-10 PSI and see if it holds) to confirm that is the problem.

Mark

 

[drumbum]

I had one (3200, basically the same saw) that would start and run for a few minutes then flood. I ended up replacing the carburetor when the original would not hold pressure even after replacing the diaphragms and lapping the needle.. Try to pressure test your carburetor (pressurize the fuel inlet to around 9-10 PSI and see if it holds) to confirm that is the problem.

Mark

Thanks for the reply Mark. Put a line on the inlet (plastic barb on right) It blows right through. Had done this previously.

 

[Gumneck]

I recently acquired a 3516 with another saw I wanted. Fuel lines and bulb rotted, so tor it down and cleaned it up (regrets). Lines are hooked up properly. Saw will run without the carb installed, so coil good, but floods with carb installed.

Had the carb apart and put a fresh pump diaphram and metering sheet and gaskets. Still floods. Needle looks good as well as the seat.

I would have sworn no one was in this saw previously...but...

Never had this kind of trouble with a carb.

Any known issues with these Walbro WT 438's?

I had a problem with a carb one time that ended up being the wrong spring under the needle valve arm. It was of course an older saw, I replaced all the soft parts in the carb, and until I pulled the carb from another exact saw I didn't realize the spring was a different length. Swapped spring problem solved. Maybe just something else to check, good luck.

 

[heimannm]

It should hold pressure, if it does not that is where you need to begin. Check the needle and spring, sometimes lapping the needle with a bit of fine abrasive (I use toothpaste) will fix it.

Mark

 

[leecopland]

Is a PM320 worth fixing? This one had the chain sharpening device but mostly gone now. P&C look great came with a nice 16" bar and chain. Seems heavy enough to have some quality built in.

 

[heimannm]

They are good runners for a 2.1 In3 saw, but working on them can be a challenge. There is a lot going on in the airbox between the impulse line, fuel line, throttle cable, throttle lock, and the choke. The fuel line can be a test as well.

Mark

 

[leecopland]

I just had a bit of a fiddle with my 320 and WOW you weren't kidding about so much going on under the carb cover. I'm also guessing that carb is only used on these small macs. I don't know why your shipment has been sitting 50 miles away for a week but hey there is this thing called Covid!

 

[MacAttack]

Thanks for the reply Mark. Put a line on the inlet (plastic barb on right) It blows right through. Had done this previously.

Your inlet needle lever could be bent far too high, contacting the diaphragm too much and holding the needle open all the time. I had that problem on a Mini Mac, see my picture. Bent it down even with carb body (you should find the metering needle lever adjustment for your specific carb) and my flooding stopped.

 

[McC]

I just picked up this 310 from local Craigslist, was a little concerned when I saw solid state ignition but it has good spark. Wow it is kinda heavy, 12 lb 6 oz with bar and chain. It’s in great shape, came with a nice case and scabbard. Will go through the fuel system when it warms up

 

[Manic84]

Your inlet needle lever could be bent far too high, contacting the diaphragm too much and holding the needle open all the time. I had that problem on a Mini Mac, see my picture. Bent it down even with carb body (you should find the metering needle lever adjustment for your specific carb) and my flooding stopped.

View attachment 889816View attachment 889817

I've always found it amusing when metering levers are set too high like that. It's almost like it's giving you the finger.
"Alright, let's open the carb and see what's wrong... Oh look! It thinks I'm number one!"

 

[MacAttack]

I've always found it amusing when metering levers are set too high like that. It's almost like it's giving you the finger.
"Alright, let's open the carb and see what's wrong... Oh look! It thinks I'm number one!"

If there's one thing I hate to see, it's when I open something up to work on it and see the tell-tale signs that some neanderthal had been poking around in it previously. Carb screws with marred heads, gobs of silicone, things missing. Then I know it's going to be that much harder to fix. And then you also wonder whats missing or assembled wrong!

 

[PogoInTheWoods]

That's when you just tear it all the way down and start from scratch doing it right.

Sorta like an incompetent cobbler of a boss or supervisor 'helping' troubleshoot a problem or issue when it finally gets handed off to you for an actual solution. I had one (boss) in a past life who was an absolute classic. Whatever he said he already covered is what I would automatically check first.

 

[Manic84]

If there's one thing I hate to see, it's when I open something up to work on it and see the tell-tale signs that some neanderthal had been poking around in it previously. Carb screws with marred heads, gobs of silicone, things missing. Then I know it's going to be that much harder to fix. And then you also wonder whats missing or assembled wrong!

Ha! Some neanderthal! Oh god I can hear it in my head: "Me pray to sun god. Me smear superglue and sealant on it. Me tighten screw till Me hear crack! Me hit with club! Why it still no work?!"
Thanks for the laugh, I really needed that.
I think a member here (Tom?) called those the signs that "Mr. Stupid" had been there before you.

But seriously, projects are one thing, so you expect things to be missing or not be quite right. But honestly it's worse when some hamfisted knothead tries to "fix" it, then brings it in like this and expects you to de-f**kerize everything they did.
And then you have to figure out what's actually wrong with the machine.

 

[MacAttack]

Ha! Some neanderthal! Oh god I can hear it in my head: "Me pray to sun god. Me smear superglue and sealant on it. Me tighten screw till Me hear crack! Me hit with club! Why it still no work?!"
Thanks for the laugh, I really needed that.
I think a member here (Tom?) called those the signs that "Mr. Stupid" had been there before you.

But seriously, projects are one thing, so you expect things to be missing or not be quite right. But honestly it's worse when some hamfisted knothead tries to "fix" it, then brings it in like this and expects you to de-f**kerize everything they did.
And then you have to figure out what's actually wrong with the machine.

I remember "Mr Stupid"! Haha...i think he was usually referring to ***** customers that would bring in a saw with a dull chain hanging off the bar wanting to know why it wouldn't cut.
Honestly when Im looking at used stuff, I go after the stuff that looks like the owner never even tried to take it apart or work on it, except for basic maintenance.

 

[heimannm]

Copied over from another thread:

MM6 - fixed starter housing, short clutch cover, no brake, points ignition

View attachment 891653

MM1 - removeable starter housing, short clutch cover, no brake, points ignition

View attachment 891652

MM25/MM30/MM35 removeable starter housing, short clutch cover w/brake, points ignition

View attachment 891654

MM110/MM120/MM130/MM140 removeable starter housing, long clutch cover w/brake, points ignition

View attachment 891655

Pro Mac 155/Pro Mac 165 were like the 110-140 except they have an extended rear handle similar to the SP40/PM510/PM515 models and a bump out in the clutch cover to accommodate the oversize muffler.

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After that there were 160S, Eager Beaver and PM3200 versions with electronic ignition

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There were quite a few other variations including Silver Eagles, Montgomery Wards, and even some unknow/unlabeled orange model.

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I probably have others as well but after a while it is hard to keep track.

Mark

 

[Mnmacguy]

MM25/MM30/MM35 short clutch cover w/brake

I think some early MM25/30 models didn't have a brake. I have a couple that way and a quick check of the July 1976 IPL shows both clutch covers, one with a brake, one without.


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[drumbum]

Your inlet needle lever could be bent far too high, contacting the diaphragm too much and holding the needle open all the time. I had that problem on a Mini Mac, see my picture. Bent it down even with carb body (you should find the metering needle lever adjustment for your specific carb) and my flooding stopped.

View attachment 889816View attachment 889817

Thanks, this carb has the recessed area and the lever is level down in there. Had the carb apart and no signs anyone had been in there, just stiff diaphragms.

 

[MacAttack]

Had been on hiatus working on my saws for a while with other projects. Finally got around to tearing down my MM25 (again...) to address the check valve in the carb. Got the welch plug out OK and got inside the check valve. I found this crude scrap of material in there as a "check valve". I'm assuming this was probably not doing the job? I ran the carb body through my new ultrasonic cleaner, next step will be trying out making a new check valve with my leather punch and an unused carb diaphragm.