Big Macs for breakfast

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cpr

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I'll have fun Sunday running these, plus the 791R and the Root. I'll get vids up. Then I need to quit screwing around and get back to building the kartsaw :biggrinbounce2:.

Ssssuuuurrrreeee.

I spent the weekend doing what I had to and at 4 I decided it was time to do what I wanted to with 60 minutes until dark. I loaded out the 125c, 791r, 440, and the Root. First, I tried to start the 791. Fuel flowing, but no go. Not even a pop. OK, to the 125. Eats it's prime nicely. Also tries to relieve me of my left hand 4 times, including back to back. Oh, and there's the time I flipped it when I forgot to push in the decomp and the saw followed what was left of my hand.

So, my left arm's a foot longer now, let's try the 440. Yep, eats prime, but no worky either. One more go at the 791.

Nope. Must have goofed something when I regapped the ignition. It should have at least popped. Then again, maybe she just hates the cold.

Now it's 4:50, the sun's gone behind the trees and I haven't tried the Root. Well, at least it ran. Even got it dialed in enough to cut fairly well. Need to touch up the chain I threw on it. Too dark at that point for shooting a video.

Tonight I changed out the 125 carb for the dual needle. Tuning it won't be fun because this is a late-model and has no window in the airbox to access the needles. Haven't tried to check out the 791 or the 440. I'm too whipped and the shop is COLD tonight.

To be continued...
 
In The Weeds

In The Weeds

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I must be on this forums too much cuz I knew which "Mac" it was referring to almost instantly.
Besides, you can't have big macs for breakfast, they dont serve em till after 11 AM :biggrin:
Nice saw btw, mean and green.
The really good thing about the vid is that in a few minutes you made enough shavings to last your hamster a week.
 
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cbfarmall

cbfarmall

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Those spitback collector sponges always turn into a sticky, crumbly goo. Those carb bolts/nuts are indeed a PITA to turn on the top-tank Macs. I'm going to grind a 7/16" wrench tomorrow morning for just that purpose. There's the one instance where the front-tank saws are actually easier to work on than the top-tank saws.

Oh.......................and you SUCK Charles!:D

I keep a set of small ignition wrenches handy for just this reason. The right angle open end is especially perfect for that left side nut close to the sidewall. I use a standard 7/16" wrench to keep the bolt from spinning or just jam a screwdriver against the flats.

Nice thing is Mac made it easy by slotting the intake flange so you only have to loosen the nuts rather than completely undoing them. I can swap those carbys in about 5 minutes.

Chris B.
 
heimannm
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Once you get it going you will like the 440, a bit heavy of course compared to a modern 87 cc saw but lots of guts and the automatic oiler makes it a more practical to actually used from time to time.

175 PSI compression on the SP125? Both of mine are around 155 and while it is possible to start without the compression release, you have to be aware and change your technique.

For the adjustable carburetor on the one SP125 I used the SDC18 of my CP70 but I had to add the port and nipple for the impulse line. Adjusting is a pain since the screws are in the wrong place but the difference in performance is notable. I don't use that one for heavy sawing, just for play. When I have some work that requires it, I still use the saw with the fixed jet carburetor to make sure there is plenty of fuel and lubrication available.

Mark
 

cpr

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I keep a set of small ignition wrenches handy for just this reason. The right angle open end is especially perfect for that left side nut close to the sidewall. I use a standard 7/16" wrench to keep the bolt from spinning or just jam a screwdriver against the flats.

Nice thing is Mac made it easy by slotting the intake flange so you only have to loosen the nuts rather than completely undoing them. I can swap those carbys in about 5 minutes.

Chris B.

Excellent call Chris. I keep forgetting I have a set of ignition wrenches. I'll have to try that tonight. I feel a carb night coming on.
 

cpr

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Well, that SDC20 sure got her to wake up. No grab handle shennanigans either. Jeebus this thing is LOUD!!!

Not sure why the cellphone camera made it appear to be plutonium-powered, but you get the idea. Log destruction is coming.

<iframe width="560" height="315" src="http://www.youtube.com/embed/0y-6tjgCiwE" frameborder="0" allowfullscreen></iframe>

BTW, I think the 791R ate another condensor. I'll fix that tomorrow and hopefully work in a Shootout Rematch.
 
rwoods

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Well, that SDC20 sure got her to wake up. No grab handle shennanigans either. Jeebus this thing is LOUD!!!

Not sure why the cellphone camera made it appear to be plutonium-powered, but you get the idea. Log destruction is coming.

<iframe width="560" height="315" src="http://www.youtube.com/embed/0y-6tjgCiwE" frameborder="0" allowfullscreen></iframe>

BTW, I think the 791R ate another condensor. I'll fix that tomorrow and hopefully work in a Shootout Rematch.

I'm glad you got her going. Mine don't glow in the dark like yours but they're still a lot of fun to run. Ron
 

cpr

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Had a little time this morning between meetings.

<iframe width="420" height="315" src="http://www.youtube.com/embed/82xR6IESZOA" frameborder="0" allowfullscreen></iframe>

The 791R was fixed with another condensor. It backed up it's previous times in this log and actually gained a second. It's a fast saw.

<iframe width="420" height="315" src="http://www.youtube.com/embed/h9OCgmjRCPY" frameborder="0" allowfullscreen></iframe>

However, the SP-125c with square grind is faster. Much, much faster.

<iframe width="420" height="315" src="http://www.youtube.com/embed/YWPa8tFMQB8" frameborder="0" allowfullscreen></iframe>

Going to have to try them with the same bar and chain...
 
Urbicide

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Well, that SDC20 sure got her to wake up. No grab handle shennanigans either. Jeebus this thing is LOUD!!!

Not sure why the cellphone camera made it appear to be plutonium-powered, but you get the idea. Log destruction is coming.

<iframe width="560" height="315" src="http://www.youtube.com/embed/0y-6tjgCiwE" frameborder="0" allowfullscreen></iframe>

Radioactive paint? I like the plutonium powered look! That is an awesome image. The sound track isn't too shabby either! This should go in "The All Things McCulluch" section.
 

cpr

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1 carb kit later and the 440 is disturbing the peace. It's been a good day.

<iframe width="560" height="315" src="http://www.youtube.com/embed/vfXxq35RYjg" frameborder="0" allowfullscreen></iframe>
 
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