SELLING McCulloch Pro Mac 850

[Bill G]

This is a used McCulloch Pro Mac 850. I have had this saw for quite a few years, and it has just sat on the shelf. It is in pretty clean condition but since it has sat, I am sure it will need a carb kit and fuel system work. The 80cc McCulloch saws in that series are darn strong saws. Over the years I have had all the saws on the series…the SP80, SP81, Pro Mac 800, Pro Mac 805, Pro Mac 850, and Double Eagle 80. There are a lot of folks that want the saws in that series. I figure it should be worth $475 plus UPS

 

[Bill G]

Pics

 

[Bill G]

Pics

 

[Bill G]

Pics

 

[YoungSawman05]

PM'd

 

[Jusgunn3]

Man, missed this one but second if it does not sell

 

[Bill G]

I had some questions about the model tag, decomp, and a compression reading. I took some pictures this afternoon. The decomp has been plugged. The compression is good at a tick under170 psi. When I took the compression reading the starter cord was starting to fray so that will need replaced. I think the question regarding the model tag was if it is a 850 or a different model @heimannm can weigh in he chooses

 

[Bill G]

Pics

 

[Woodslasher]

Randy's Engine Repair lists 600072B as a Pro Mac 800 made 8/80-9/81, for whatever that's worth.

 

[YoungSawman05]

Hey eveyone its me the buyer. I got a question for yall. Im assuming its impossible to find the DSP plug for these PM800 cylinder shrouds anymore correct? Also, how hard would it be to interchange the muffler. I dont need the EPA muffler, and plus it would make me gain some power. What mufflers can I switch it out with? I saw on another thread that a SP81 muffler, and Pro Mac 850 muffler is interchangeable, but they said the old Pro Mac 850 muffler so I am not sure whats the differences in what mufflers I need/want to open this baby up.

 

[Jusgunn3]

I’m sure it rips as is, not sure about the muffler swaps. Have fun with that baby!

 

[Cat 525]

They always said the 81 was like a ported saw anyway. Cut lots of walnut with them and the 850's. They run well the way they are. And remember if you are doing any flush cutting the exhaust is bouncing right back at ya.

 

[YoungSawman05]

They always said the 81 was like a ported saw anyway. Cut lots of walnut with them and the 850's. They run well the way they are. And remember if you are doing any flush cutting the exhaust is bouncing right back at ya.

I wish I had a SP81. Ive tried to get one but everytime I do someone else gets to it before I Can. Do you have experience with the PM800s? This will be the fist 80cc mac that is actually my property so I am just seeing how you like the PM800's. I just heard from other people that run them that the mufflers were there downfall.

 

[Cat 525]

All of the 800 series i ran i didn't have a problem with any mufflers. Only thing I thought was bad was the placement. Logging walnut half your cutting is flat on the ground and if it was dry it would give you a dust shower constantly. Or snow in your face if snow on the ground. But that was part of it.

 

[JimG.]

I have three runners in this series. 81, 800 and 850. Of those I found the 800 to be the lowest performing. I replaced the awkward muffler with an 850 style simple one and advanced the timing up to 30*. It still was sluggish which I blamed on the Q port until I realized the coil was slowly failing. With a replaced coil it runs very well and is the most well behaved idling saw of the three I have. It is the only one of the three I can start without a decomp. due to the Q port.
It is possible Mark Heimann, @heimannm, will have some or all of what you are looking for. If he does not and if you do get the saw you can PM me. I have a homemade muffler that will work on that saw if you are interested.

 

[Squareground3691]

I have three runners in this series. 81, 800 and 850. Of those I found the 800 to be the lowest performing. I replaced the awkward muffler with an 850 style simple one and advanced the timing up to 30*. It still was sluggish which I blamed on the Q port until I realized the coil was slowly failing. With a replaced coil it runs very well and is the most well behaved idling saw of the three I have. It is the only one of the three I can start without a decomp. due to the Q port.
It is possible Mark Heimann, @heimannm, will have some or all of what you are looking for. If he does not and if you do get the saw you can PM me. I have a homemade muffler that will work on that saw if you are interested.

I did the same thing, made the saw performance way better, the 800 muffler was a terrible design,

 

[heimannm]

600072 is a PM800 as noted. That muffler and the bolt suggest is has the Q port and was not intended to have a compression release, The pop up DSP valve on those were 3/8-16 threads PN 215673 and installed in the same spot as that bolt through the muffler strap you see in the photo above. I do have a few good used and NOS DSP valves if one is needed.

My own experience says the PM850 is the best running of all the 82cc models but I can't say that I've ever done a fair side by side test with and 850 and 800 models. I do know I have one 800 that I did a little dressing around the exhaust port to clean up some areas in the casting I thought were rough and the performance of that saw was quite good.

Some are critical of that large muffler that is mostly under the engine, of all the 82cc models the ones with that muffler make the least noise and I think for some folks that is perceived as a detriment to performance.

The PM800, 805, 8200, and Double Eagle 80 cylinders do not have the two bosses for the 80/81/850 type mufflers to attach so if you plan to use the other muffler type it will be necessary to make other arrangements to fix the cover on the muffler and support the muffler on the saw. The exhaust port overall shape and location and mounting holes on the bottom of the engines are the same so the 80/81 and 850 tyle mufflers will bolt to the bottom.





Mark

 

[YoungSawman05]

I’ll probably pass on the DSP valve since they weren’t designed for the Q-Port. I am however still interested in purchasing a muffler that’s a SP81/PM850. I can make it work somehow for supporting the muffler. Thanks for the info!

 

[Bill G]

I am glad to see some good information posted. The question is @YoungSawman05 after you have read the comments do you still want the saw? You have already paid for it and I will be packing for shipping tonight. I would love to get it sent out to you but I do not want hard feelings. I never want to mislead anyone.

Bill

 

[nv656]

I’ll probably pass on the DSP valve since they weren’t designed for the Q-Port. I am however still interested in purchasing a muffler that’s a SP81/PM850. I can make it work somehow for supporting the muffler. Thanks for the info!

I would run it first with the muffler you have before swapping. You’d have to adequately support it to prevent cracking at the brazed seams, also it fits right up against the cylinder and mounting holes are through holes for the reed plate. More of a hassle per any sort of improvement I’d think.