McCulloch Chain Saws

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check out the spikes on this 1-50.

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Mac 20

Randy Mac,
That Mac 20 is great! I had one of those on a Bug kart. Same exhaust header. It had dual carbs into the crankcase and at one time a third carb on top. Also had a MC 10 with a stroker crank with 1/8 inch head gasket and a stroked MC 5 which made it a MC 6..had a thin ring piston.
Ran on methanol and Blendzall.

May have blown the 20. I had one where the wrist pin needles got out into the cylinder.
Willysmn
 
The Super 250 has more aggressive porting, and a longer stroke (1.5" vs. 1.375") giving it a displacement of 87 cc vs. 80 cc.

All of the Super 250's I have seen have a McCulloch flat back carburetor with a choke, something that is rather unique amongst the Mac's.

Mark

Some of my Super 250's have the tillotson carb,HL 63 A
It shows in the IPL they came with the flat back or the
tillotson
 
I have a pair of McCulloch 660's as well, one with McCulloch/Walbro flat back carburetor w/primer, one with Tillotson carburetor and choke. From the lables on the saws it is evident they came from the factory that way.

I think some of the very early Super 250's had the Tillotson carburetor, probably the same vintage saws as the yellow top's, later ones with the black top with extra holes had the flat back. I have heard that early Super 250's were still 80 cc saws, later ones added the extra throw to the crank shaft and became 87 cc's.

What makes the flat back used on the Super 250 and 550 saws really unique is the choke, I believe they are the only two models to come from the factory with the flat back/choke version.

I am still waiting to get my first Super 550, but I do have a couple of standard issue 550's, one of which I plan to bring to the PNW GTG at Farley's in a couple of weeks.

Mark
 
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Looks like you decided not to pop that nut out before painting the top cover...

Can you look carefully at the two cylinders and see any appreciable differences like more holes, bigger holes, etc. that would distinguish the differences in the porting?

Mark

Yeah I opted to leave it on didnt like the possibility of it not going back together right. Over all side by side I dont see any differances between the two. Wendsday I will try to strip that down all the way and take pictures of the ports side by side. From the out side they look the same.
 
Here ya go Randy and Cliffy,
This came in today, Model Super LG2 and
came with this bow bar. Not sure if
it's original to the saw. But looks good.
And runs well also. Just needs a muffler
or just the muffler cover. Hint, Hint.

Lee


MccullochLG2Bowsaw001.jpg

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Ok I had some time after dinner and here is a 250 side by side with a Super 250.
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The 250 has dividers but everything looks the same in size.

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The 250 is on the left.

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Super 250 piston is on top but both connecting rods look the same in length. The Super 250 crank is on the bottom and looks to be a little wider as well as tapered on the clutch side. Length of bore looks the same to me and port size looks the same. Im almost wondering if I have a 80 cc Super 250. According to the serial number it looks like it is supposed to be a 87 cc. If anybody sees any differences I dont let me know, I dont really see where the 7 cc comes from.

Leeha nice looking saw, was that the one on ebay? I think I was looking and dreaming on that one.

On a side note, todays lesson is dont scrape gaskets with a razor towards your fingers. You end up painting your bench red and jumping up and down like an idiot on the driveway swearing.
 
While we are on the subject of 250s, this is my favorite one. I either going to replace the starter with a nice yellow one or paint it match the airbox cover. This seems to be an early 250, the model number looks to have been stamped over an older designation. The fuel tank front is a left-over, converted oil tank from the 1-40/50 series. I put the bells and whistles on it, fullwraps, rear hand grip, 3/8" rim sprocket, Flatback to Tilly 63E conversion, "porthole" airbox cover, flywheel cover from a Super 250, and muffler. The bar has a 34" cut from the tip of spike,
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Here ya go Randy and Cliffy,
This came in today, Model Super LG2 and
came with this bow bar. Not sure if
it's original to the saw. But looks good.
And runs well also. Just needs a muffler
or just the muffler cover. Hint, Hint.

Lee


MccullochLG2Bowsaw001.jpg

QUOTE]

Looks to be in nice shape Lee. Well I might of had a muffler cover
but you called me the wrong name so I don't think
I could look for it now.:cry:
 
I have two timber faller buddies- one is named #### and he doesn't like to be called Richard. The other one is Richard and he doesn't like to be called ####. I have to be real careful and remember which one is which.
 
I got this real nice Double Eagle 80 a few weeks ago. It came with
no bar and chain. I had the bar and I made up a chain for it.
It runs real nice. Thanks again BillG.:cheers:

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Cliff- that's a nice 'un. Now with one of those plastic cowboy hat-hardhats and some knee-high rubber boots, you'd have the complete outfit for a log cutter from Mountain Home, AR.
 
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