McCulloch Chain Saws

[vinnywv]

Jethro, if you want that old school sound then find a mufflee from an 850. I did the same as ron and put one on my 800. It sounds just as great as the 700 and seems to have a bit more snap. It may be in my head but it does scream awesome! There is a bit of modification to do though. The original muffler is huge and covers the entire bottom of the saw engine providing air flow through the engine cooling fins off the flywheel. When you take that big muffler off you must take that into account or you will overheat and mess up your saw. Whatvi did was useca peice of sheet metal or flashing and fit it around the exhaust outlet and up to the cooling fins so the airflows through the fins still. A few pictures. as you can see theres a large gap without tbe stock muffler. Lots of air will bypass the cooling fins.

 

[vinnywv]

Looks like i messed up that last picture and put it in as a thumbnail instead of full image..sorry.

 

[Pine Marten]

New addition to the stable. I picked up a Pro Mac 10-10 off Craigslist. It started on the 6th pull and ran on the 7th. Revs well, settled down to a stable idle, oils the bar very well. Now I've gotta clean it up and sit it beside its big brother my Pro Mac 60..... ..for now it is visiting its cousin in Oregon.

 

[rarefish383]

Anyone here ever do any mods to a pm800 muffler. My pm700 sounds amazing and as you guys know we run these old saws cos we injoy them. The smell the vibrations the history that sits ting ting ting tinging away waiting patiently for its wot thrashing like it has done for decades well the 800 just doesnt have that sound to it imho and its not as nice to tune because of the noise eather and.... who really wants or needs a quieter 82cc saw? If your not wearing ear protection with a chainsaw then you probly never have and probably couldnt here the dam 800 at all by the time it came out any way so yea end of the ramble. Ear plugs and muffs l want to be needing with a old big heavy chainsaw mite as well get the hole experience.

Not too mix the Red saws up over here. But, I was thinking about trying to see if the stack muffler off my C72 will fit on one of my Super 1050's. That should take loud to a new level. Oh, those Macs? I can't hear them at all, sound like lectric saws to me.

 

[Jethro 2t sniffer]

Thanks vinny I'll see if i can track 1 down if nothing shows up i may look at building one. Its only steel after all and i did wonder if i would need to make up a shroud so those pics help heaps. Ive never had the saw apart properly yet as it tuned up fine and was clean so no real need too.

 

[rwoods]

Anyone here ever do any mods to a pm800 muffler. My pm700 sounds amazing and as you guys know we run these old saws cos we injoy them. The smell the vibrations the history that sits ting ting ting tinging away waiting patiently for its wot thrashing like it has done for decades well the 800 just doesnt have that sound to it imho and its not as nice to tune because of the noise eather and.... who really wants or needs a quieter 82cc saw? If your not wearing ear protection with a chainsaw then you probly never have and probably couldnt here the dam 800 at all by the time it came out any way so yea end of the ramble. Ear plugs and muffs l want to be needing with a old big heavy chainsaw mite as well get the hole experience.

Ron has I think a 850 muffler on his 800. Not sure of the performance gain, but it is loud.

Brian

I am with Brian on this, though there is a fellow on another forum that probably has forgotten more about MAC performance than I know that swears the duct type mufflers outperform the 800 style. All I know is my 800s with stress holes in the muffler seem to run better than those that don't have any holes and my 800 with the duct seems to have the same power as those with a hole or two. Many say the older saws outperform the 800 while MAC claims the 800 has more ponies. If the porting is the same, I will only believe MAC's claim if the older saw they compared had the fine mesh spark arrestor as the 800 when clean appears to have more area.

Jethro, if you want that old school sound then find a mufflee from an 850. I did the same as ron and put one on my 800. It sounds just as great as the 700 and seems to have a bit more snap. It may be in my head but it does scream awesome! There is a bit of modification to do though. The original muffler is huge and covers the entire bottom of the saw engine providing air flow through the engine cooling fins off the flywheel. When you take that big muffler off you must take that into account or you will overheat and mess up your saw. Whatvi did was useca peice of sheet metal or flashing and fit it around the exhaust outlet and up to the cooling fins so the airflows through the fins still. A few pictures. View attachment 663861 View attachment 663864 as you can see theres a large gap without tbe stock muffler. Lots of air will bypass the cooling fins.

Here is what I did with mine. That nice SP81 cover with the reed I saved and I simply run a plate in which I drilled a grid.



Ron

 

[rwoods]

Ron

 

[Jethro 2t sniffer]

Ok ron so where abouts are these stress holes? Im also wondering if i could cut it open and build a duct up to the screen and keep the rest of the muffler there as the air shroud. I've never had it off so i really dont know if thats do able or not. Im thinking this way as the 850 muffler is hard to find

 

[rwoods]

"Stress holes" is just my shorthand for quarter size chunks of a 800 muffler missing due to stress cracks meeting around the area of that supports the screen. I don't think I have any pictures.

Several of my 800 purchases had muffler screens that were almost completely clogged. As you likely know saws need to breathe. My first SP125 had the muffler replaced with one of the round cans with the adjustable outer grill. I thought it ran great but several who knew better ran it at a GTG and told me it was just okay. When I took the muffler off to replace it with a kart muffler I found the inner perforated plate was almost completely clogged with rust flakes. It is like a different saw now.

I think a new shield would be easier to make than modifying the old muffler to be the shield - mounting points etc. The 850 duct muffler body comes up for sale with some frequency. The hard part to find is the cover. You can make the inner plate. I made mine using a hand saw, drill press and grinder.

Ron

 

[rwoods]

And you don't need a muffler cover if you run any of the more modern long clutch covers. Ron

 

[rwoods]

Picture of inner plate. The broken clutch cover is now history. More holes were later added to the grid. Ron

 

[Pine Marten]

2 stroke exhaust theory is weird science! I think I would make a bunch of plates with various sized holes and test them buried in a log at WOT to see which produced the best power. I would be willing to bet that the best power producing baffle plate would still have that sweet sweet McCulloch sound!!!

 

[Jethro 2t sniffer]

Ok thanks ron thats givin me plenty of info and ideas to work with. Im starting to wonder if i just build my self a hole new muffler i know it seems silly but to me its great fun and is what i like to do.

Martin it is certanly a science i had a old 84 kx250 with a severely squashed up and beat in expansion chamber and i spent countless hours of research and built a new 1 for it in 15mm sections it took a long time but in the end worked great. I learnt alot about sound waves and how to speed them up and send them back just as the port closes too early or too late is very bad and theres a small window of just right and in that window you can adjust the power a little. Throw in ignition' port timing and jetting n yup science allright.

 

[Brian Thacker]

The problem is the lack of space on a saw to build a exhaust that really works. I have built many exhaust on our race bikes through out the years. A saw is just kind of let the exhaust all out and hope for the best. No real way that I can see to get the proper back pressure and the right or the sound waves. Most 2 strokes need a certain amount of back pressure to work right, How to get this on a saw I don't know.

Brian

 

[Jethro 2t sniffer]

The problem is the lack of space on a saw to build a exhaust that really works. I have built many exhaust on our race bikes through out the years. A saw is just kind of let the exhaust all out and hope for the best. No real way that I can see to get the proper back pressure and the right or the sound waves. Most 2 strokes need a certain amount of back pressure to work right, How to get this on a saw I don't know.

Brian

Yea way to small wonder if they (mac) was allmost on to something with the read valve idea back pressure and waves maby it got rather expensive and gave up. I like the power pipes on race saws but just ugly and impractical on a work saw

 

[chainsaw _ crazy]

I know this isn't the mac I should have this bar on but it looks pretty similar to the mounting set up on the super pro 81 as far as I can tell. The Oregon bar was never actually used paint is still in the groove and the sproket teeth are very pointy and the only wear are a few scratches and a light rust spot

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[Jethro 2t sniffer]

Very nice old bar

 

[chainsaw _ crazy]

Very nice old bar

Thanks I love the older ones they definitely where made very well

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[Jethro 2t sniffer]

Yea ive got a 24 same older type the paint is well gone but the rails are hardly warn ive heard the newer Oregon stuff isnt as good

 

[rwoods]

More 800 action tonight. Didn't quite match that first cut. Threw the chain and buggered some drive links on the back side of the first cut. New chain . Base was just a tad over 4'. If I had known ahead of time I would have brought a 125 for some exercise. Ron