McCulloch Chain Saws

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Good to know. I have a PM 850... is it comparable to that?
I have a couple minty DE80's I haven't had a chance to run yet. The 800 looks very similar to them.

MAC claims the 800 has more power than the 850 but there are some users here that may say differently. I don't know as the 850s I used to have were well worn. DE80 is internally the same as the 800 & 805 but with a different carb and intake set up. There been some speculation that the coil is different as well but I haven't heard the followup on that. I suspect that they will run about the same. My former DE80 was well used so I can't really say. I can say that I have several 800s and an 805 all of which run well but some are notably stronger. Only difference I can tell is a hole in the muffler for one and a little stronger compression in another. Ron
 
My PM850 is much stronger than my PM800 or any other 82cc Mac. It's not modded and its compression is better than the others. Mark can vouch for that statement. I still think that the "Q" port relieves too much compression. My 800 had a good cylinder and the rings look great but it's just too easy to pull start it.
 
I think all the 5 cube 10x Macs are the best of the McCulloch lot, yeah I would like a 125 and a 797 but they would mostly be show saws, the top of the 10 series are great cutting saws I usually take one with me every time I go cutting and they get used as much as any of my more modern saws. I will say my PM850/CP70 is my strongest of the lot, it is also my most temperamental, my fixed jet SP81 is the most reliable and easiest starting, just runs a bit rich at WOT.
 
According to the Mac literature, the addition of the Q port on the PM800 reduces the need for a compression release valve and provides increased HP and cutting speed.

I don't have a really fresh version of the DSP saws yet (parts are in the attic) but the difference between a fresh PM800 and so so SP81 are very clear, even factoring in the better noise from the SP81.

Joey, next time you're up will will have to try to make an honest comparison between you 850 and the better of the PM800's to see what we can see.

I will say that at Baraboo last fall a very nice running 250 was top of the 5 In³ class, my SP81 was well down the list, and a super running 10-10 (with a first class operator) took second.

attachment.php


Mark
 
Mark, I might have one. I'll check and let you know. Ron

Mark, I have a brace that matches the one in the SP81E IPL. Whether or not it is the same as a SP80, I don't know. It has a small crack in the bottom but it appears serviceable. Let me know if you want it and I'll send it to you for Christmas. Ron
 
Some time this summer a friend of my younger son stopped by with a pickup load of large oak rounds and a D-44. Apparently I had agreed to take a load of wood in exchange for making the old McCulloch run again.

We spend a few minutes that day going through the carburetor and replacing the fuel line but couldn't get anything more than a pop.

I finally got to it, decided the compression was probably too low to fire reliably so I torn it all the way down to give it a good cleaning and replace the rings. Surprisingly the cylinder and piston were in very good condition, perhaps 0.001" combined wear wear between the tow. The first ring I tried to install broke the second I put it in the ring expander but I was able to find another ring in the attic.

Fuel tank was in bad shape with a lot of very hard varnish in the bottom and some corrsion on the top so I did a little chipping and sandblasting and the tank was ready(or so I thought).

I had the gaskets needed on hand and got it back togeher eventually. Seemed like it took a couple of hours to get the rear handle back in position and get all the linkages reconnected and operating correctly. The governer was all mess up as well and that took an hour or so to get right again.

Finally got it all back together and discovered there was tiny pin hole in the top of fuel tank, I'll leave that for the owner to take care of as I'd already invested over 10 hours in this project.

Now it starts and runs decently, hopefully Josh can get it back to the rightful owner before I get back from Australia on 10 December.

attachment.php


attachment.php


attachment.php


attachment.php


attachment.php


Mark
 
i.d. assistance . 250? some mac stuff is fun to i.d. my super 250 has no #s on it?
attachment.php

Fraser my friend your luck keeps on going. I spent a good amount of time going through Mac piston/cylinder/rings charts as well as many IPL's and just couldn't find a match to the block number in your pic (63436). Went through a few more IPL's and finally found it. Matches the cylinder part number for a 99cc 550.:cheers:

I can't remember for sure what # was on the 550 that I had. It now belongs to RandyMac. For some reason, 63436 is coming to mind as being the number that is on that particular 550. One more thing perplexes me however; Your block doesn't look to have an unmachined boss for a DSP valve. Every 550 and S-550 that I've seen has that boss...

100_3760.jpg

The boss I speak of is just hiding behind the body of the muffler clamp in this pic. If I'd shot a 'quartering away' pic of the right side of the 550 then we'd been able to see the boss (or if I'd taken a pic of the right side of the saw when I first got it from Mark, as it had a stack muffler at that time).
 
Last edited:
thanks bud. turns over smooth and the p/c look good. now to dig for some parts and make it live again. just about got things squared in the shop so i can start getting to them . still have some things for ya. just got behind on things.:msp_rolleyes:
 
thanks bud. turns over smooth and the p/c look good. now to dig for some parts and make it live again. just about got things squared in the shop so i can start getting to them . still have some things for ya. just got behind on things.:msp_rolleyes:

No worries my friend. I'm way behind on a bunch of things as well. You're going to really like that saw. About the same size/weight as a 250, but with MUCH more ass. I miss that 550, but am glad it's in Randy's hands. I swapped a Tillotson HL63 on to the 550 when I had it. Something went 'wrong' with that flatback carb between Iowa and here, and I couldn't get it right again..........so I just swapped on the tilly.

If you swap an HL63 (sourced from a 250 or one of the many other front tank Macs) in place of that primer-flatback, you'll need the cast 'adapter' plate that goes between the carb and the manifold. The adapter plate will hopefully be on the donor saw. Flatbacks only use a thin stamped steel 'indexing' plate on those saws. Impulse holes are in different locations (and the cast adapter fixes that). The thicker cast adapter also spaces the carb back to the proper location for the AF stud to line up with the cover. Flatbacks have longer 'snouts' to make up for the difference.

Randy swapped an early 'short' yellow AF cover in place of the 'mailbox' cover on the 550 shortly after he got the saw from me. Maybe you can work something out for the original 550 cover since it's probably just sitting in a box now...
 
Last edited:
McCulloch SP80

E-bay purchase, didn't go too high. Advertised as an SP80, certainly the lable says SP80 and it does have a few details that lead me to believe it is/was an SP80 such as the style/design of the fuel cap, roller fairlead on the starter, the muffler is right, it has the spring on the boot rather than the ground wire on the front anti-vibe mount.

The clutch is a typical 10/600 Series two shoe affair and the regulation three shoe SP80 clutch does not fit the crankshaft. I don't know if that means this one has been rebuilt using other parts or if some SP80's came from the factory with the other crankshaft.

This one arrived with a broken rear handle (happened in shipping). I contacted the seller and we agreed to a small refund amount. I haven't seen the refund appear in my PayPal yet so we shall see...

attachment.php


I did not bother taking a bunch of photos during the process but it was pretty straight forward tearing it down, cleaning it up, and getting it back together. Just a few small items here and there were needed to make it quite servicable again.

I was pleased and surprised at the condition of the piston and cylinder. I measured the bore and the piston and they were in remarkably good condition. In fact, within my capability to measure, they were like new according the McCulloch piston/ring/cylinder list I have. Since I had a set of rings on hand I went ahead and put the new rings in. I used a brace (bottom/rear handle piece) from another project I have underway so now I will have to substitute the one Ron has so graciously offered on that saw.

Anti-vibe parts were in great condition, boot was very good, I did replace the impulse line and the metering diaphragm and gasket in the carburetor and the fuel line. Oh yeah, the coil was loose on the laminations. Looked like the retainer clip was broken allowing the coil to flow around and drag on flywheel. For this project I decided to use a coil I worked on a few week ago with Ray and Moody were here with a new spark plug wire attached. I had to adjust the length of the spark plug wire and repair the ground lead but in the end using the original points and condenser I had a nice hot spark. It came with a 20" McCulloch bar like you'd find on a 600 saw but I've never seen any bar as badly chipped as this one so I added a 24" sprocket nose (Echo) bar I had on hand. I think that one actually came out the the big box!

Got it all together in the afternoon and surprise, surprise, it starts, idles, accelerates, oils, even the stop swith works! All in all a very fun project. You will notice in the photos that the original black parts have been repainted rather sloppily with a grey that is reminescent of the PM4200/8200 color scheme. I will leave it as is for now but this one might just get a full restoration as some point in the future. Sure wish the crankshaft was original, I would like to have one SP80 with the three shoe clutch in it.

attachment.php


attachment.php


attachment.php


attachment.php


Mark
 
Last edited:
Back
Top