McCulloch Pro Mac 850 or Pro Mac 800

[Dave P 71801]

I get to pick between these 2 saws as payment for some work on a 372xp that I would normally charge $60-70 for so I think its a good deal.

I know the bubbles in the paint are oxidation so can I re paint the 850 and it stay or will it start to bubble real quick?

This is what I saw in a quick inspection:

Pro Mac 800 has 130lb of compression, good spark, the paint is definitely nicer, but it shows more signs of use, the guts are missing from the muffler, all the av mounts are completely shot, and the clutch cover has a crack.

Pro Mac 850 has 155lb of compression spark is ok, shows less signs of use, it's 100% complete, but the paint is bubbling basically everywhere, no cracks or chips I see, and the av mounts are decent

 

[rwoods]

My two cents:

As noted the 800 appears to have seen more use. I would say it has been road hard and put up wet - not good. It also has the wrong clutch cover and muffler. The older muffler might be a good thing but the correct muffler also acts as a cowling to direct air flow across the cylinder. I don't see any evidence of a replacement cowling (this would be a custom piece) - not good. It's compression is pretty low - a good shape one should have around 165#. It clearly has been "into" by someone - might not be good. A/V are shot = $50 to $75. Some MacNuts say the 850 has better performance; not my experience but every saw is different.

An 850 in decent shape should have compression around #175. The tank/handle assembly could be replaced at a much less cost than the 800's A/V mounts, clutch cover and muffler. The 850 has a more desirable wide belly bar.

Assuming a peek in the cylinders show they and the pistons are good, my vote would be the 850 though I no longer own any and have more than a 1/2 dozen 800s.

Ron

 

[Dave P 71801]

My two cents:

As noted the 800 appears to have seen more use. I would say it has been road hard and put up wet - not good. It also has the wrong clutch cover and muffler. The older muffler might be a good thing but the correct muffler also acts as a cowling to direct air flow across the cylinder. I don't see any evidence of a replacement cowling (this would be a custom piece) - not good. It's compression is pretty low - a good shape one should have around 165#. It clearly has been "into" by someone - might not be good. A/V are shot = $50 to $75. Some MacNuts say the 850 has better performance; not my experience but every saw is different.

An 850 in decent shape should have compression around #175. The tank/handle assembly could be replaced at a much less cost than the 800's A/V mounts, clutch cover and muffler. The 850 has a more desirable wide belly bar.

Assuming a peek in the cylinders show they and the pistons are good, my vote would be the 850 though I no longer own any and have more than a 1/2 dozen 800s.

Ron

I was kinda leaning to the 850 my only concern is the bubbling paint well actually its the oxidation that is causing it because its not limited to the tank/handle its also on the fan shroud, oil tank cover, clutch cover basically everywhere except the black bottom pan. If I can sand it all down, prime and re paint and it stay I'm ok with it but If it will continue to come back no matter what I do then I will probably look at the 800 a lot harder.

 

[Jethro 2t sniffer]

The parts that are going rotten are easy bits to find i wouldn't worry about them its the engine health that matters most and also like Ron says AV mounts are expensive. I repaired mine due to that cost.

If that 800 doesn't have a cowl underneath i wouldn't grab it over the 850. Also the 850 is more desirable due to the performance thing. I also lean with Ron here i have both saws in great shape and the 800 is no slower at all infact in 24inch wood i would say its quicker. The 850 can hold off a stall better with the 32 that's about it.

Grab the 850 for sure and quickly before its gone hell of a saw

 

[Jethro 2t sniffer]

offer some money for the 800 too at 130psi the cylinder might be Sweet and its got alot of goodness on it still. Running theres 500 bucks easy on the bay. Run run run as fast as you can before the fox grabs your Mac's. Some of Mac's very best too

 

[Goinwheelin]

Grab the 850

 

[Dave P 71801]

I own the 850 now we are negotiating on the 800.

 

[Dave P 71801]

Will I be wasting my time to try to sand and repaint the 850? If it was steel I would know how to deal with it but because its alloy I just don't know what to do or how to do it or if I should do it at all.

 

[Dave P 71801]

It's official I got stung by the Bumblebee now I've got the yellow fever

 

[Dave P 71801]

Did a tear down and cleaning and the Piston is absolutely gorgeous also found some markings can someone tell me what they mean?

 

[Dave P 71801]

I also have a hard decision to make do I stick with the original Reed muffler or do I go to the slightly older style louvered Muffler I have one of the louvered Mufflers that's brand new nos

 

[Dave P 71801]

Decisions decisions

 

[Dave P 71801]

I had to make a new impulse line out of Tigon and the spring out of a pen.

 

[rwoods]

"A" means it takes an "A" piston. Slightly narrower than the "B". Widest is the "C".

Factory specs call for 32 to 1 mix while other MAC models of the same time period were 40 to 1 - in other words I recommend you use 32 to 1 despite all the fussing over ratios.

Post your paint questions over in the MAC sticky thread.

Ron

 

[rwoods]

Decisions decisions

View attachment 841778

You have the long clutch cover so I would stick with the reed. Someone with an older saw will lay out a few coins for the louvered muffler. Ron

 

[Jethro 2t sniffer]

Well done mate. I think the read style is restrictive. Did you get the 800 too?

Keep on the hunt for a new tank and other bits
Seems a waste of paint and effort to try and fix up white rust

And yes come on over to the yellow pub

 

[Jethro 2t sniffer]

You have the long clutch cover so I would stick with the reed. Someone with an older saw will lay out a few coins for the louvered muffler. Ron

That is a point it would look good on an 81

 

[rwoods]

I am not seeing a brake band on the 800. Ron

 

[Jethro 2t sniffer]

I am not seeing a brake band on the 800. Ron

Good spotting

 

[Dave P 71801]

Yea its broken off the 800. Can someone tell me what mounted where there is no paint? There was nothing when I took it apart so I curious about what is missing.