McCulloch Chain Saws

[Brian Van]

What's the difference between the sp80 and the promac 800

 

[Brian Van]

Ooooo I want to play with this one!

 

[joeymt33]

What's the difference between the sp80 and the promac 800

In my opinion, the SP 80 is more desirable. It is lighter weight and performs better with a longer bar. The PM 800 is heavier, quieter and has probably more RPM

 

[Brian Van]

In my opinion, the SP 80 is more desirable. It is lighter weight and performs better with a longer bar. The PM 800 is heavier, quieter and has probably more RPM

Which is your favorite?

 

[joeymt33]

My favorite is a tie between the SP80, SP81, and PM850.

 

[Brian Van]

I grew up with the pm 700, but I got a John Deere 80ev someone was throwing away. It's a monster! 700 wins in my eye's.

 

[BigBlue]

Rob - I hope to have an electronic file so someone with a 3D printer can produce the sawdust screens for the 10 Series saws. I expect to have a prototype made in PLA in November, but I suspect any "real" parts will need to be manufactured from some other material. If someone can recommend a reasonably priced 3D printer that works with materials other than PLA let me know and maybe I can get one and try to produce the screens myself.

It is possible that the duckbill valve in the fuel cap was not sealing properly, on most 10 Series saws that would produce a drop or two from the fuel cap onto the top of the fuel tank even when the saw is setting. Maybe it just needed a bit of "wet time" to soften up and seal correctly again.

Mark

Interesting about the 3D printer thing. That would be cool. I imagine in 5-10 years we're going to have all sorts of additional capabilities that are going to make life easier in this regard.

As for the fuel cap thing, the wicking was happening repeatedly after I removed the cap. It was either wicking up from the side of the tank due to a leak from the new cork gasket between upper/lower tank halves or it was wicking up from the main bolt going through the center of the tank cover. Either way pretty odd to me.

Rob

 

[BigBlue]

Red Kote is a good option for any of the tanks that are sealed (anti-vibe 10 Series models, etc.), but with the reproduction rubber gaskets available from e-Bay now days I would hesitate to seal the tank on any of the models with a removable top. That said, it is no trouble to fish the fuel line through the fill opening in the top of the tank to replace a fuel line without taking the tank apart. I generally reserve removing the tank top for saws that require a more substantial cleaning.

Mark

That's my take on things too, to not use Red Kote on a split tank. And yes, I've had to fish the fuel line in/out through the tank opening several times now and it works decently.

I think some of my issues stem from the fact that the paint around the top/bottom half lips is either coming off or loose. I suspect this makes the seal difficult due to minor material thickness differences and allowing fuel to seep under loose paint. I hesitate to sand/scuff all the paint off the lips because I think that will accelerate the paint issue on the tank sides. And I'm not to the point to being willing to totally dismantle things to sandblast all the old paint off and repaint it "the right way". Fingers crossed, I hope I have things licked now!

Rob

 

[PogoInTheWoods]

I grew up with the pm 700, but I got a John Deere 80ev someone was throwing away. It's a monster! 700 wins in my eye's.

Don't cut that 80EV short. I have one and it's a very strong saw built like a tank..., except for the sprocket cover which is hard to find..., (like a PM850 in decent shape for under $500!).

 

[BigBlue]

Is the screen the "214192 mcculloch"? I have it on ebay search and do get a email every now and then but the bid gets into the stratosphere and I never win one. For $40+ I will make one/two out of stainless screen for my 10-10a and Promac10-10....
My 7-10A if I'm not mistaken, is different with the roller type starter, and has 3 seperate pieces?

The parts list for the 10-10 Automatic I have lists that screen as 87674. However, for my 10-10S it is 214192 and the pictures look pretty much identical for them. Here are all three saws lined up to show the recoils (the middle is the PM700, for which I have no parts list):

Rob

 

[dynodave]

View attachment 601260 View attachment 601261

Ron

Here is my 7-10A (1-72) MOD 600052 SN10-16472 with 3 83598 screens as you have shown...except out of shape a bit

 

[brandonstc6]

Does anyone have any experience with the mc100 kart engines? I am looking for the parts numbers for standard seals. Can Standard rollers in appropriate size be obtained from a bearing supplier. I lost 2-3 or the rollers for the connecting rod.


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[rwoods]

Thanks, dynodave. I can see the difference in the three legs. They stick out further and are meatier than the other covers. I checked my covers and found two types of legs - some "finished" like the 7-10A but noticeably smaller and set back and some "I beam" style and also set back. The screen groove on both styles goes all the way around instead of from leg to leg. Ron

 

[BigBlue]

Questions on a Pro Mac 800:

I got this one for free that "used to run but hasn't worked in a while". Looks like it is in decent shape so I figured it would be fairly easy to make it run. I just haven't been able to get it to fire. At first it seemed like it was getting too much fuel so I got a Zama carb kit for it (it has a Zama C3). Installed that last night. Carb looked pretty decent inside. Some varnish and a couple pieces of debris. Old diaphram was in one piece but pretty 'old'. Got it all cleaned and re-assembled. I'm pretty confident it went together correctly.

I have what looks like good, strong spark. I've tried a different plug from a 700 (known working). New fuel. Fuel still seems to be getting to the cylinder. However, it really just will not fire. I've even tried squirting a little gas in the plug hole or shooting a small (very) burst of starting fluid through the carb. Only maybe twice in all the pulling have I gotten it to fire for 1-2 seconds. Those times it fired it sounded pretty normal. Sometimes it sounds like it wants to go (like starting a saw that has sat for a while - that sound just a pull or two before it finally fires) but this has me baffled. It seems to have compression because it is harder to pull over when the plug is in versus removed. But it really doesn't feel much tougher than my 10-10 when compression release is pushed. Is that a sign of a cylinder/piston issue? I don't have a compression gauge.

Could the coil be bad even though it shows good spark when I pull the plug and turn it over? Is it possible it is out of time and firing at the wrong time? I have a spare coil from the 10-10/700 I could try. Looks like the part number is the same.

One other question. When I had the carb off I was looking to see the piston's condition and when I pulled the recoil I could see the piston moving but the top never came back past the intake port. Is that right? It just looked wrong. I thought it had to pass it to get the intake charge into the compression chamber?

Thanks!
Rob

 

[boda65]

Questions on a Pro Mac 800:

I got this one for free that "used to run but hasn't worked in a while". Looks like it is in decent shape so I figured it would be fairly easy to make it run. I just haven't been able to get it to fire. At first it seemed like it was getting too much fuel so I got a Zama carb kit for it (it has a Zama C3). Installed that last night. Carb looked pretty decent inside. Some varnish and a couple pieces of debris. Old diaphram was in one piece but pretty 'old'. Got it all cleaned and re-assembled. I'm pretty confident it went together correctly.

I have what looks like good, strong spark. I've tried a different plug from a 700 (known working). New fuel. Fuel still seems to be getting to the cylinder. However, it really just will not fire. I've even tried squirting a little gas in the plug hole or shooting a small (very) burst of starting fluid through the carb. Only maybe twice in all the pulling have I gotten it to fire for 1-2 seconds. Those times it fired it sounded pretty normal. Sometimes it sounds like it wants to go (like starting a saw that has sat for a while - that sound just a pull or two before it finally fires) but this has me baffled. It seems to have compression because it is harder to pull over when the plug is in versus removed. But it really doesn't feel much tougher than my 10-10 when compression release is pushed. Is that a sign of a cylinder/piston issue? I don't have a compression gauge.

Could the coil be bad even though it shows good spark when I pull the plug and turn it over? Is it possible it is out of time and firing at the wrong time? I have a spare coil from the 10-10/700 I could try. Looks like the part number is the same.

One other question. When I had the carb off I was looking to see the piston's condition and when I pulled the recoil I could see the piston moving but the top never came back past the intake port. Is that right? It just looked wrong. I thought it had to pass it to get the intake charge into the compression chamber?

Thanks!
Rob

I'm just a novice, but I'll attempt an answer. The knowledgeable regulars will be along shortly to add to what I say or correct me if I'm wrong. It could be out of time, you would have to pull the flywheel to see if the key is sheared. Also check the coil lamination to flywheel gap, it should be about .010. As for the piston, the fuel air mix is pulled into the crankcase under the piston, where it travels through the transfer ports into the cylinder. You won't see the top of the piston unless you peek through the spark plug hole.

 

[PogoInTheWoods]

I believe I would be dropping the bottom plate and removing the muffler for a look at the piston for scoring (or for some other cause for low compression). A PM800 has fairly stout compression..., at least mine does. Sounds like you may be right on the edge of having enough for the saw to run, but 85 ~ 90psi (which is pretty low) should still allow it to fire up.

 

[joeymt33]

I'm just a novice, but I'll attempt an answer. The knowledgeable regulars will be along shortly to add to what I say or correct me if I'm wrong. It could be out of time, you would have to pull the flywheel to see if the key is sheared. Also check the coil lamination to flywheel gap, it should be about .010. As for the piston, the fuel air mix is pulled into the crankcase under the piston, where it travels through the transfer ports into the cylinder. You won't see the top of the piston unless you peek through the spark plug hole.

Everything you have said is accurate. Good idea on checking the flywheel key, that would've been one of the first places I would look also.

I would also guess that the saw has a scored piston on the exhaust side. Seems that a lot of them do.

Another thing about the 82 cc versions of the ProMac is their compression can be deceiving when comparing to the smaller versions. I have found that these saws do not like to run very good when under 150 psi and they really run poor when they get down to 130. All the 82 cc saws that I have are between 160 and 200.

 

[BigBlue]

OK, I'll disassemble things to try to get a look at the piston through the exhaust port. As for the flywheel, how hard it is to pull that? Take the recoil off and just use a gear puller, or is there a special tool needed?

Thanks,
Rob

 

[boda65]

OK, I'll disassemble things to try to get a look at the piston through the exhaust port. As for the flywheel, how hard it is to pull that? Take the recoil off and just use a gear puller, or is there a special tool needed?

Thanks,
Rob

MOST have two 1/4-20 threaded holes. Use gear/steering wheel puller.

 

[joeymt33]

OK, I'll disassemble things to try to get a look at the piston through the exhaust port. As for the flywheel, how hard it is to pull that? Take the recoil off and just use a gear puller, or is there a special tool needed?

Thanks,
Rob

I have always been lucky enough to get the flywheel to come off with several taps from a dead blow hammer. If not, then you'll need to use a puller.

If you pull the muffler off, make sure you clean the threads and the screws real good and use some blue Loctite and new lock washers when reassembling. Those are notorious for coming loose and ruining the threads.