McCulloch Chain Saws

[stinkbait]

With the stock carburetor (.687 venturi and fixed high jet) my saw tops out around 10,000-10,500 out of the cut, definitely four strokes. With the SDC in place and adjusted a bit I could hit 11,300 RPM and still some 4 stroke. When we got to the woods to test it, I did richen the SDC about 1/8-1/4 turn as it was obviously lean in the cut.

In the woods today - to try and keep it even I put 36" hard nose bars on each saw, and new off the reel chains. Unfortunately the bars were differents (one .058 and one .063) though both are Carlton chisel.

You could definitely tell that the one with the SDC/adjustable carburetor would rev higer in the cut, yet seemed to pull as hard and keep going. This is the stock saw

Mitch thought the modded saw pulled better too

If all goes well, I will switch them around and try it again next weekend to make sure it's the carburetor making the difference and not the saw/bar/chain. I did recheck compression on each when we got back today and the SDC equipped saw was right at 150 PSI, the stock carb saw about 155 PSI. I would not have thought that a slight change in the venturi size and adjustable jet would make so much difference, at this point I am thinking it really does. In the end, I will probably keep one stock for those days I need to run a few tanks of fuel through making firewood, and keep the other for GTG's and such.

Mark

Im glad that we could make you a believer of the adjustable sdc carb. I also put one that size on my newly build sp81, and that saw will scream. Now all the adjustable sdc carbs on fleabay just went up $10 more.

 

[1375619cm3]

mac 1-51 starter

Well guys I took a look at the starter assembly on my mac 1-51, it is differant than the 50,52 saws judging by the ipl for those saws. I'm still trying to figure out how she comes apart so I can fix the recoil spring in it could use some help if anyones got an idea. Would also like to look at an ipl for the 1-51 if anyone has one I received an ipl for the 50&52 but they r just differant enough from the 51 to make me a tadd bit confused.

Also with the saw sitting as long as it did I probly need to take the carb apart to clean it and was wondering if I needed to buy a rebuild kit for the seals to put it back together or not the saw was runnen great when it was shut off 20 years ago so I know the carbs got probly just dirty and a little varnished. Thanks for the help everyone.

 

[RandyMac]

Is the spring broken or just really dirty? If the spring is ok, use a can of WD40 on it or soak it in something nice.

 

[RandyMac]

Working from faulty memory. Remove that thin cover from the outside of starter housing. The spring lives under the cover. Be ready for a fast clicking rattle, a sproing, followed by a rapidly expanding snarl of flat steel.

 

[RandyMac]

I might have that wrong, the sproing comes first.

 

[1375619cm3]

mac 1-51 sprin

Im pretty sure the spring is broken I can free spin the assembly. Do u know how the end of that shaft that mates to the crank housing comes off. Is it threaded or pressed n if its threaded is it lft or rt hand threads.

 

[dieselsmoke]

Try LH first, if your'e looking at the 2 pronged nut shaped deal. On the inside of the recoil housing.

 

[HeRoze]

Okay - What did I just buy? :msp_biggrin:

 

[cpr]

890 or 660 is my guess. Most unusual muffler...

 

[RandyMac]

A 1-80 series maybe, there will be numbers on the bottom. Does the head bolt on?

 

[cpr]

Could be Randy. Did the later 1-80s come with the faultback? The early ones had the HL.

 

[cbfarmall]

Okay - What did I just buy?

I see 640 on the AF cover--scratched or scraped into the dirt.

Chris B.

 

[rwoods]

Guessing from the AF cover and the general apppearance I would say a 640. I believe this was a popular model for running bows in the mid sixties. I agree the muffler does look odd - the directional can is more usual in my limited experience. Ron

 

[HeRoze]

890 or 660 is my guess. Most unusual muffler...

better shot of the muffler from the bottom:

 

[HeRoze]

I see 640 on the AF cover--scratched or scraped into the dirt.

Chris B.

Great eye. What I see on the bottom is something like "225" with 'X's over each digit. Under that, there is a fairly clear "650"

 

[rwoods]

better shot of the muffler from the bottom:

I don't believe that is a stock muffler. Looks to me to be modified. Ron

 

[rwoods]

Great eye. What I see on the bottom is something like "225" with 'X's over each digit. Under that, there is a fairly clear "650"

It's a 640. You can see the 4 if you look close. The 650 was the direct drive version. Ron

 

[HeRoze]

It has to be the heaviest friggin' saw I've held. If you had it, would you find it worth fixin' up? Only thing that is missing is the cover over the coil/sparkplug (although I bet that will be a PITA to find).

 

[rwoods]

Stuck engine.

Seeing all these bow saws today led me to check on my 1-60 which I last ran over thirty years ago. It's stuck. And that's a shame as it's internals were super clean. What is the best way to free it? In my youth we use brake fluid to keep engines from sticking and for freeing them. Thanks, Ron

 

[HeRoze]

It's a 640. You can see the 4 if you look close. The 650 was the direct drive version. Ron

That is kind of unusual too, the "640" looks like a 5 and a 4 are overstruck on the middle digit.