Mcculloch 850 Pro Mac build.

[Adirondackstihl]

Cuts quite nice!!

Sure did!
Was fun to noodle with!

 

[jacob j.]

DE80 - Q port and pop up compression release

To be continued...

Mark

Very cool Mark- my grandpa had a mint Double Eagle 80 that he bought new at Crater chainsaw in Medford, Oregon way back when. He traded it in the late 80's though for a new canopy for his pickup. It was a fine runner.

 

[Al Smith]

Went from a build thread to a deep discussion. lol

These saws were so far advanced for the time period very few actually know much about them .The only big deal is because of how they were made there really isn't much you can do with them to enhance them .This one ,the 82 cc Macs have as big of a cult following as 2100 Husqvarna ,I have both so I guess I'm in two cults .

 

[Al Smith]

I must have forgotten to " submit" on the question of Q port and decomp on the 805 . Give me a couple of days .I have a set of 12.4 by 28 tractor tires arriving tomorrow .I have to find the decomp that comes out the side instead of the end like an 850.I think it held the bracket for that screwed up screened muffler. -- I have to get my old Ferguson going and can't do it with a flat tire . Ya gotta do what you gotta do .

 

[heimannm]

We're good Al - it finally registered in my brain that is a SHCS sticking out of the top of the 805 cylinder and not a pop up style compression release. That opening just above the muffler on the PM8200 cylinder is tapped 3/8-16 and requires a peculiar pop up compression release to fit it, or a 3/8" long bolt to hold the brace on the top of the muffler.



My DE80 had a PM8200 short block in it when I got it that had the Q port and the pop up compression release. You can see the exhaust port with the Q about 11:00 and the port for the DSP/compression release about 3:30.



Finally, the pop up DSP valve in position with the brace for the muffler.



But this is supposed to be a PM850 thread so more PM850 stuff



Mark

 

[TJ the Chainsaw Mechanic]

Howdy folks, found another cylinder and it should be here late this month. Looks to be in decent shape. Now to just hurry up an wait.

 

[TJ the Chainsaw Mechanic]

Well this build has not been forgotten about! haha The cylinder I found off ebay ended up being junk as some of the chrome was peeled off. Couldn't see it in the pictures and the seller said it was a Good used cylinder. Yeah.....anyhow...found an SP81 that was burned up. Was able to salvage the cylinder off of it. Some sanding with 320 and a good honing and I couldn't feel anything with my nail. Now to getting it together! Beginning with the tedious process of putting the needles in place on the crank and where I left off for the evening. Should have it done tomorrow....maybe....we'll see.

 

[Al Smith]

Regarding bad chrome I think McCulloch had some quality problems during that time period .It may have been a problem due to not being able to get that hard Rhodesion chrome or their process .However it was about the time you didn't see as much chrome on automobiles as there once was .----put some grease on those needles.makes it a whole lot easier .

 

[TJ the Chainsaw Mechanic]

Regarding bad chrome I think McCulloch had some quality problems during that time period .It may have been a problem due to not being able to get that hard Rhodesion chrome or their process .However it was about the time you didn't see as much chrome on automobiles as there once was .----put some grease on those needles.makes it a whole lot easier .

Yup! Did the grease, my they kept flying out of my fingers. haha

 

[Steve]

Looking good!

 

[TJ the Chainsaw Mechanic]

Thanks Steve! Well she looks like a saw again. The fuel line I ordered that was supposed to be a "direct replacement" was not correct at all. The large part of the hose that fits in the tank is to small and the hose length from the tank to the carb is to long. *Sigh* Gonna try some 1/4 fuel line for now and go from there. Shop is closed until Tuesday so off to Napa in the morning for fuel line. But I am stoked to see it back together. Next is cleaning up the handle and figuring out some sort of rubber to put back on. Might paint the handle black at the aluminum probably won't polish out to good.

 

[J. Loe]

That is a big old pig and I can’t wait to see her running again.
Fantastic work sir!


Sent from my iPad using Tapatalk

 

[Coutu]

A brass wire wheel on a drill will clean the handle up. You can follow that up with some scotch brite too to get an even better looking surface.

Looks like it came out well. Good job!

Matthew

 

[TJ the Chainsaw Mechanic]

Thanks guyz! Trying to sort out an air leak or something. Saw fires right up, but doesn't want to idle very well and tends to load up. Carb has been cleaned and rebuilt...holds pressure and the metering lever is set where it should be. Thinking it may be sucking air or some bar oil into the crank case causing it to load up. Gonna order all new pump gaskets and a piston assy.....shoulda done that in the beginning.

 

[TJ the Chainsaw Mechanic]

So I think I narrowed my air leak problems down to the auto oiler not sealing against the crank case. Have a new gasket on order for that as well as a new piston assy, manual pump gasket, and tank cover gasket. Hoping those will solve my problem. Really wanting to get this thing in some wood.

 

[peter92]

So I think I narrowed my air leak problems down to the auto oiler not sealing against the crank case. Have a new gasket on order for that as well as a new piston assy, manual pump gasket, and tank cover gasket. Hoping those will solve my problem. Really wanting to get this thing in some wood.

TJ . does your oil pump have 1 screw holding it in and did you use the spring plate at the back of the pump , im up to that part now but cant bend the plate, i cant see what holds the plate when its bent as theres nothing for the top of the plate to clip in to
Peter

 

[PogoInTheWoods]

The plate is simply wedged into place. And sealant should not be required with the pump gasket.

 

[peter92]

The plate is simply wedged into place. And sealant should not be required with the pump gasket.

Yes havent used sealant on the gasket
how far back do i need to push the plate back
Peter

 

[PogoInTheWoods]

You just need to get the plate wedged into place to the extent that it has a bit of an arc to it. Going too far can actually bend it which requires straightening and flipping it around and going from the opposite direction, but whatever temper it had has been compromised and it may bend again in the opposite direction. Two screwdrivers (one on each side of the pump) is the best method to push the top of the plate into position. The above stated, I'll qualify it by admitting that my experience was with a copy of an OEM plate that could have been less rigid than an original.

 

[peter92]

You just need to get the plate wedged into place to the extent that it has a bit of an arc to it. Going too far can actually bend it which requires straightening and flipping it around and going from the opposite direction, but whatever temper it had has been compromised and it may bend again in the opposite direction. Two screwdrivers (one on each side of the pump) is the best method to push the top of the plate into position. The above stated, I'll qualify it by admitting that my experience was with a copy of an OEM plate that could have been less rigid than an original.

ok thanks so it doesnt have to be pushed right back , ill try it tooro and see how i go
Peter