McCulloch Chain Saws

[Brian Thacker]

http://randysengine.repair/collecti...eries-pm10-10-55-chainsaw-randysengine-repair
A little cheeper
https://store.chainsawr.com/collections/mcculloch
This guy might have them. Go to contact and ask
https://www.m-and-d.com/MAC-M64330.html

 

[fossil]

Really? I only see a couple out there, mainly on eBay, and they are close to $20 each. I was hoping someone here might have a line on some that were a bit more affordable.

If you're handy and have some sheet steel, drill, files and a hammer, they aren't hard to make. They don't have to be exact, just shaped to keep the chain guided.

If you want a scanned part which will print to exact size from a pdf file I can do that for you.

 

[leecopland]

Picked this up. Runs great. Throws a large amount of bar oil so that will need to be adjusted.

I really like the 70cc series. I find these saw are great for noodling as the chips clear the cover very well.View attachment 524381 View attachment 524382 View attachment 524383

Is that one off K? I looked at one a week or so ago but decided I needed to divest some more first. That looks like a super unit, good score.

 

[fossil]

Is that one off K? I looked at one a week or so ago but decided I needed to divest some more first. That looks like a super unit, good score.

Yes. I picked it up in Lindsay on my way up to Minden. A good runner as it was. Heck. the fuel and oil tanks aren't leaking either and the duckbill in the fuel cap is working.

Front handlebar is bent a bit back and it could use a new muffler cover. I expect to use it. Old hardnose bar on it is pretty worn. Still happy with the buy.

Next time you come by, you need to run it. I think you'll be impressed. They don't vibrate like a 10-10

 

[rwoods]

I ran my 7-10 (rings were pretty fresh) against a mint PM700 and the 7-10 was faster every time. I think perhaps they changed the porting on the PM700 to gain some life from the saw.

The 82cc models all had pretty aggressive porting as well, to the point that McCulloch recommended running 32:1 in all of them to avoid problems.

Mark

Can't comment on the 7-10 PM700 comparison, but I can say the performance difference between my PM700 and my 82cc MACs is much greater than displacement alone would indicate.

Ron

 

[BigBlue]

Thanks to both of you. I'll give those ideas a shot.

Rob

 

[asulliv2]

I inherited a Pro Mac 700 from a friend - first attempt at chainsaw rebuild (regretting this endeavor at the moment. I noticed that a significant portion of the muffler reed valve was cracked off (part# 71 in diagram below). Can someone tell me a.) what function this serves and b.) if I need it, what the fix options (if any) other than buying the replacement part from Randy's or Old Mower Parts, etc.?

Many thanks to Mark (heimannm) for previous help on air tank seal!

http://www.searspartsdirect.com/model-number/promac700model60011604/0684/1503200.html

 

[fossil]

The purpose of the reed was to reduce exhaust noise. If you don't mind the noise, you should be OK.

Here's the McCulloch patent application for the reed type mufflers. It gives you an idea of what's accomplished and why.

https://www.google.com/patents/US3318412

 

[heimannm]

McCulloch replace the internal baffles in their mufflers with the reed as shown in that parts drawing starting in 1969 but applied somewhat sporadically through the '69 and '70 models. They made some pretty bold claims about the noise reduction with the reed mufflers, but considering the noise level from the old baffled mufflers most anything would have been an improvement. The reed type mufflers were still in use in into the early '90's on some models, others had been supplied with an internal baffle and spark arrestor screen in the late 80's. As in all things McCulloch, it appears to have been pretty random in the beginning and at the end of its use.

Watch e-bay in addition to the other sites, those parts do show up from time to time. Some have made their own replacements out of equal gauge stainless steel material.

For saws with the vertical muffler and internal baffle (see the attached illustration) I have a whole pile of the baffles and can make anyone a very attractive offer. In fact, on several of the reed type mufflers the baffle and be installed instead.

Without the reed the saw will be louder, I think the only potential harm you could do would be if another fragment broke off and was sucked back through the exhaust port. The noise will be pretty loud so make sure you have hearing protection.

Mark

 

[fossil]

Good detailed description. Judging by the few I own, I don't think they made too many quiet saws. I have a couple of other brand saws that are worse though.

 

[svk]

Hi guys. Here's a head scratcher at least for me.

Put a carb kit (Walbro SDC) in my 2-10/10-10 frankensaw. Saw runs great now but wants to die immediately when being tipped on its side. Burping the throttle keeps it running and runs fine at high speeds. It's not like it's running out of gas but I'm wondering what would cause the immediate poor running at low speed?

 

[fossil]

That's usually a good indication of a bad crank seal or possibly starving for fuel if you are tipping it clutch up. Try it with a full tank of fuel. Another indication would be a slow return to idle or a very inconsistent idle speed.
I've found several times an old saw that hasn't run for some time will run fine for a bit and then the seals will give up.

I have a similar situation now with a 7-10A I picked up.

 

[svk]

That's usually a good indication of a bad crank seal or possibly starving for fuel if you are tipping it clutch up. Try it with a full tank of fuel. Another indication would be a slow return to idle or a very inconsistent idle speed.
I've found several times an old saw that hasn't run for some time will run fine for a bit and then the seals will give up.

I have a similar situation now with a 7-10A I picked up.

Thank you.

Someone else locally mentioned seals and I was afraid of that.

This saw sat from 96 when my buddy's dad passed until I got it running this summer.

 

[fossil]

They are very easy to change on those saws. Not sure what chassis you are using but if the PTO side is MAC PN 110260 use an SKF CR6119 seal.
If the MAC PN for the FW side is 61618. use Timken 471551.

 

[svk]

They are very easy to change on those saws. Not sure what chassis you are using but if the PTO side is MAC PN 110260 use an SKF CR6119 seal.
If the MAC PN for the FW side is 61618. use Timken 471551.

You read my mind! I was just on eBay looking for them and had figured out mag and pto were different.

The shortblock of this saw was an early 2-10 with the bullfrog carb. Do you think those aforementioned part numbers are correct for that saw?

 

[fossil]

FRom what I can fins the PN on you PTO seal is 65747, 81580 go to 110260 so the CR 6119 should be good

The FW side 65746 crosses to 61618 which is the same as Timken 471551

Pull the clutch, flywheel and ignition points assembly and measure the crankshaft surface where the seal rides as well as the ID of the case where the seal goes to make sure those seals will fit

SKF CR 6119 dimensions are OD for 0.875" case bore X 0.625" shaft dia

Timlken 471551 fits case bore dia 1.37"

Flywheel crankshaft 0.5625"

 

[svk]

FRom what I can fins the PN on you PTO seal is 65747, 81580 go to 110260 so the CR 6119 should be good

The FW side 65746 crosses to 61618 which is the same as Timken 471551

Pull the clutch, flywheel and ignition points assembly and measure the crankshaft surface where the seal rides as well as the ID of the case where the seal goes to make sure those seals will fit

SKF CR 6119 dimensions are OD for 0.875" case bore X 0.625" shaft dia

Timlken 471551 fits case bore dia 1.37"

Flywheel crankshaft 0.5625"

Very much appreciated, thank you!

 

[Brian Thacker]

OK, Rebuilding my PM55 after the clutch retaining washer broke and the clutch bell trashed the case and cylinder. While I had it down I tore down my Super 10-10 and my regular 10-10 to replace the seals in them and to inspect the cylinders to see if they may need new rings. I got noticing the carbs on all 4 saws because I have had my 10-10 Auto torn down for some time just being lazy not putting it back together after replacing the crank seals. Any how one would think that all the 10-10s would have the same carb and the PM55 would have a larger carb. Well the PM55 has a SDC 49 with a bore of .78 inches. The Super 10-10 has a SDC 16 with a bore size of .76 Inches the 10-10 regular and the 10-10 Auto has a SDC 37 with a bore of .82. Now my questions are.
1. Why does the PM55 have a smaller carb than the 10-10 and 10-10 Auto?
2. The PM55 has fixed main jet meaning that there is no high speed adjustment. Does anyone know of a reason that I could not put a SDC 37 carb that has the high speed adjustment on the PN55? The performance gain would not be much if any with only increasing the bore size by .04 inches. But that would give me a high speed adjustment. Any commits?
3. Putting a SDC 37 on the super 10-10 would give it a .06 inch bigger carb and that might give it a little more power?
Just rolling some things around in my head.

Thanks
Brian

 

[rwoods]

Put one of these on the Super if you want it to be super.

Just kidding. I know diddly squat about carbs.

Ron

PS to Brian: I am still waiting to hear about the oak. They are still waiting for the "log" guy to show.

 

[Brian Thacker]

Does anyone know where their might be a chart that would tell you the bore size for a Walbro carb. I can find one for a Zama but not the Walbro. Their is no rhyme or reason on there numbering scheme.
By the way Ron I need 4 of those super carbs...lol

Brian