McCulloch Chain Saws
- Thread starter Bruce Hopf
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Boda, RE: the reeds, the IPL shows that as a screw together assembly, you could try to flip it over but I suspect the crankcase pressure will shut it up when you pull it over anyway.
Did you have this saw running before the teardown? Was it spitting back through the carburetor pretty badly? If it was running and not spitting back, don't worry about it.
The fuel tank gaskets is not as hard to make you you might expect, just trace around the top half and you have a pretty good pattern, you can judge from the old one how "wide" to make it. I like to clamp the two halves together and use a transfer punch or even the screws themselves to make the holes as I never seem to get them right with a punch.
I think original equipment between the tank and the crankcase was a sort of "double wide" gasket that folded over to get both side of the insulator, and another gasket between the reed plate and the tank. Certainly separate gaskets would work just as well.
I know I have one saw (can't remember which one) that is working with Indian Head gasket shellac in place of the gasket between the insulator and the reed plate.
Mark
Did you have this saw running before the teardown? Was it spitting back through the carburetor pretty badly? If it was running and not spitting back, don't worry about it.
The fuel tank gaskets is not as hard to make you you might expect, just trace around the top half and you have a pretty good pattern, you can judge from the old one how "wide" to make it. I like to clamp the two halves together and use a transfer punch or even the screws themselves to make the holes as I never seem to get them right with a punch.
I think original equipment between the tank and the crankcase was a sort of "double wide" gasket that folded over to get both side of the insulator, and another gasket between the reed plate and the tank. Certainly separate gaskets would work just as well.
I know I have one saw (can't remember which one) that is working with Indian Head gasket shellac in place of the gasket between the insulator and the reed plate.
Mark
streamlight
New Member
Thanks, briantutt for the tip,got it installed works great.
I have not run it. It was part of a small pile I bought that consisted of two 1-72's and a 1-71 that were in various stages of disrepair. My goal is to make one nice one out of the three. This one fired when primed but compression was not the greatest. I finally found a set of rings for it so am ready to proceed. I'll go ahead and flip the reeds just to play it safe. As always, thanks much for the advice.
Jim
maestro
ArboristSite Lurker
I'm starting the teardown and rebuild of a Mini Mac 6. Just for kicks and giggles really. It has sat somewhere wet for a while and looks like it needs some TLC. When I pulled the flywheel and coil I found a condenser and breaker box. Can one of you with more experience in older saws explain why a coil ignition would have a condenser and what exactly does a breaker box do? It's not a points setup that I'm familier with and if there is a coil and magnetic flywheel, why would you then need points? Is it a volt reducer? The spark plug is tiny. They are all listed on the IPL so it's all stock. Thanks!
The ignition needs a trigger, telling it when to fire, and that is what the points do. A more modern electronic ignition would have electronics built in to the coil to do the same job.
The coil itself actually consists of two sets of windings, primary with fewer turns of heavier wire, and secondary with a lot more turns but generally finer wire.
When the magnet(s) move past the coil it induces a current flow in the primary windings. When ever there is current flowing in a wire, a magnetic field is created around the wire, wrapping the wire in a coil intensifies the magnetc field.
At exactly the right instant, the breaker points open "breaking" the curcuit, the current flow stops and the magnetic field collapses. The condenser "absorbs" the voltage for an instant to prevent arcing at the points, then discharges back through the primary windings speeding the collapse of the magnetic field and increasing the voltage induced in the secondary windings.
Basically the point gap determines the ignition timing, increasing the gap advances the timing, reducing the gap retards the timing.
There are a few other threads dealing with ignition and trouble shooting that have good information and illustrations of testing the system/components with a Fluke.
Mark
The coil itself actually consists of two sets of windings, primary with fewer turns of heavier wire, and secondary with a lot more turns but generally finer wire.
When the magnet(s) move past the coil it induces a current flow in the primary windings. When ever there is current flowing in a wire, a magnetic field is created around the wire, wrapping the wire in a coil intensifies the magnetc field.
At exactly the right instant, the breaker points open "breaking" the curcuit, the current flow stops and the magnetic field collapses. The condenser "absorbs" the voltage for an instant to prevent arcing at the points, then discharges back through the primary windings speeding the collapse of the magnetic field and increasing the voltage induced in the secondary windings.
Basically the point gap determines the ignition timing, increasing the gap advances the timing, reducing the gap retards the timing.
There are a few other threads dealing with ignition and trouble shooting that have good information and illustrations of testing the system/components with a Fluke.
Mark
maestro
ArboristSite Lurker
Thanks, Mark. That's what I was looking for. I guess this saw is part of the transition between a true points system and a true electronic system. I look forward to messing with it!
The 35 carburator is quite different from the carburators we know, and was a proper design of Mc Culloch. You need probably the manual to understand its function and to set it properly. I don't have a copy of it but maybe someone else could help you out.
Turkeyslayer
Smells Great
Found this in the Fil's barn. Just wondering what model it is.
stinkbait
Addicted to ArboristSite
That's a D44
Turkeyslayer
Smells Great
Thanks for the quick reply. Now off to Mike Acres site to have a look.
77 cc's of early McCulloch hot rod. The whole 44 Series were some of the first "high speed" chain saw engines, easily capable of going over 12,000 RPM. If you didn't want the chain speed and preferred a lot of pull power on the chain, get a 55, 55A, or Super 55A, simply the corresponding 44 with a gear drive on the side.
The 44 Family
My 55, let me tell you that even with the 9/16" pitch chain this one will cut.
Mark
The 44 Family
My 55, let me tell you that even with the 9/16" pitch chain this one will cut.
Mark
And just in case you didn't see it in the Mweba thread, proud Papa with the 840 and 48" bar.
Mark
Mark
McCulloch 840 2.165 x 1.635 = 6.04 In³ or 99 cc.
The 1-85 is only 95 cc but I believe it turns out a few more RPM. I put a 2:1 gear set in mine and have equipped it with .404 chain but have not had a chance to put it into any wood yet. I am hoping the weather cooperates for Grandpatractors GTG on 13 March, I would like to run against some other gear drive saws.
Mark
The 1-85 is only 95 cc but I believe it turns out a few more RPM. I put a 2:1 gear set in mine and have equipped it with .404 chain but have not had a chance to put it into any wood yet. I am hoping the weather cooperates for Grandpatractors GTG on 13 March, I would like to run against some other gear drive saws.
Mark
Turkeyslayer
Smells Great
Heimannm, thanks for the great info and pics
. That 840 with the 4' bar is pretty badass
. That 840 with the 4' bar is pretty badass
Mr. Bow Saw
Addicted to ArboristSite
Nice pics mark. That was a big tree I saw your other thread
and videos nice job.
and videos nice job.
Mr. Bow Saw
Addicted to ArboristSite
I just got this Super 44 a few days ago.
Brmorgan
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Super 250 ?s
So I got a seized Super 250 in a trade from fellow member "jockeydeuce" the other day. I haven't had a chance to open it up yet to see what I have to work with, but will take some pics when I do. It's physically in really good condition, even the paint, just a bit dirty. Anyway I did take the top cover off and noticed it's equipped with one of the big old Flatback carbs. From what I understand these aren't the easiest things to get parts for anymore... I've read about guys rigging up a Tilly HL to work on some of the big old Macs - is it possible with a 250? And if so, what model of HL would be needed?
Also, assuming the piston is toast, where would I go about finding one if I need it? It would seem these are one of the more popular old Macs around; hopefully it won't be too hard to track down or too expensive.
So I got a seized Super 250 in a trade from fellow member "jockeydeuce" the other day. I haven't had a chance to open it up yet to see what I have to work with, but will take some pics when I do. It's physically in really good condition, even the paint, just a bit dirty. Anyway I did take the top cover off and noticed it's equipped with one of the big old Flatback carbs. From what I understand these aren't the easiest things to get parts for anymore... I've read about guys rigging up a Tilly HL to work on some of the big old Macs - is it possible with a 250? And if so, what model of HL would be needed?
Also, assuming the piston is toast, where would I go about finding one if I need it? It would seem these are one of the more popular old Macs around; hopefully it won't be too hard to track down or too expensive.
StihlGuitar
ArboristSite Operative
I just got this Super 44 a few days ago.
I think that was my saw. Did you buy it on ebay from Michigan?
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