MCCULLOCH The official McCulloch thread

[RandyMac]

Skinny skid plate.

 

[Al Smith]

Looks like it might have came of an 81 .--or the cover of an 850 on an 81.Reed cover muffler .No big deal; it looks good

 

[Al Smith]

Let me investigate .I've got the running gear of an early 850 I bought to re engine the 805 in a box .I can't remember if it had the wider bottom plate or the skinny one . I'll get some pictures .These things get hodge podeged together over the years so it's hard to say .
Neat thing about McCullochs is you could dismantel a half dozen of the same displacement ,toss the parts in a pile reassemble and they'd all run with each others parts .

 

[TJ the Chainsaw Mechanic]

Looks like it might have came of an 81 .--or the cover of an 850 on an 81.Reed cover muffler .No big deal; it looks good

The tank is an SP81 tank. I was going to repaint it yellow but like the black look better. Any idea of where I can get a fuel line? One I got that supposedly was for this model fits loosely in the tank. Heading to Napa this morning to see about some bulk line and a grommet for now.

 

[Chainsaw Jim]

If that bulk line at Napa is anything like the tygon looking bulk line at Knecht's then avoid it like the plague. That chit swells up when in contact with gas and starts slipping off the barbs. The fuel filter falls right off. It takes a few weeks but it happened to every piece I've ever used.

They sell nos fuel lines for this model all over eBay for about 12 bucks.

 

[Al Smith]

You might try MFG supply,on the net .They often have either NOS or aftermarket stuff for a lot of things .Fact I found the replacement line for a Husqvarna 2100 on the cheap .

 

[Al Smith]

I did a little research .This picture is an SP 81 with the air box cover from an early 850,direct fit .However the suspension bottom plate is the fat one which evidently is stronger than what they used on the 81 .I couldn't find my IPL for the early model 850 to compare it to the super . For all I know it could have had the skinny one but my donor saw came with the fatty .Like I said these things could have just about any part on them and still work

 

[Al Smith]

Now I'm not trying to nit pick but if that thing has a points ignition it has to be an sp 81 because that as far as I know was the only one made with a cam to operate the points cut into the crankshaft .Also the cover over the "head" area of the saw is different from an 850 but again with a saw that old it could be any number of parts .When you cut to the chase as far as performance I doubt serious if you could tell much difference .

Like I said before I've got a complete 850 engine inside the wrap of an 805 and a person would have to be very familiar with Macs to even know the difference .--see why I like old Macs

 

[RandyMac]

 

[joeymt33]

Now I'm not trying to nit pick but if that thing has a points ignition it has to be an sp 81 because that as far as I know was the only one made with a cam to operate the points cut into the crankshaft .Also the cover over the "head" area of the saw is different from an 850 but again with a saw that old it could be any number of parts .When you cut to the chase as far as performance I doubt serious if you could tell much difference .

Like I said before I've got a complete 850 engine inside the wrap of an 805 and a person would have to be very familiar with Macs to even know the difference .--see why I like old Macs

Don’t forget about the SP 80, it also had points ignition with a lobe on the crankshaft.

 

[Al Smith]

I stand corrected ,thank you .IPL date 1972,SP 81 IPL 1976.
Now that brings up something interesting .Would it be possible to convert a points type to electronic without much effort .? I wouldn't because I like points but some might be tempted.

 

[joeymt33]

I stand corrected ,thank you .IPL date 1972,SP 81 IPL 1976.
Now that brings up something interesting .Would it be possible to convert a points type to electronic without much effort .? I wouldn't because I like points but some might be tempted.

You scan convert to using the NOVA chip but not the later model coil. The mounting bosses on the jug are different.

 

[TJ the Chainsaw Mechanic]

Now I'm not trying to nit pick but if that thing has a points ignition it has to be an sp 81 because that as far as I know was the only one made with a cam to operate the points cut into the crankshaft .Also the cover over the "head" area of the saw is different from an 850 but again with a saw that old it could be any number of parts .When you cut to the chase as far as performance I doubt serious if you could tell much difference .

Like I said before I've got a complete 850 engine inside the wrap of an 805 and a person would have to be very familiar with Macs to even know the difference .--see why I like old Macs

No points on this one. If the diaphragm in the oil pump is bad could that cause an air leak? As of now it runs either to rich or to lean. Loads up and when I lean it out it dies.

 

[Al Smith]

If the diaphragm leaks it will suck bar oil into the crankcase .Many of them leak a little which is no big deal if it isn't too bad .Just smokes on start up a little bit .Too much will drown the plug and hydra lock the piston .Had that happen on a Mini 120 .

 

[TJ the Chainsaw Mechanic]

If the diaphragm leaks it will suck bar oil into the crankcase .Many of them leak a little which is no big deal if it isn't too bad .Just smokes on start up a little bit .Too much will drown the plug and hydra lock the piston .Had that happen on a Mini 120 .

I think mine is getting just enough to load it up and die as it actually runs better if I pump the manual override quickly.

 

[Al Smith]

I've never had any luck rebuilding the pumps .I must be doing something wrong .I suppose you could crank the pump piston down so the auto oiler doesn't work at all then use the thumb if worse comes to worse .
I'm not sure if the pumps from say a 700 would interchange with the 81's or not .
On the little 120 I had to block off the impulse line and use the thumb.Talk about a pain in the buttocks to work on .

 

[heimannm]

The automatic oil pumps are the same on all the 10 Series saws. Earlier saws had three screws to hold the automatic pump in place an used thinner gaskets. Later saws have one screw and a spring clip that wedges it in tight enough to get a good seal.

For the fuel line, a few wraps with Teflon thread tape will seal it up.

Mark

 

[TJ the Chainsaw Mechanic]

The automatic oil pumps are the same on all the 10 Series saws. Earlier saws had three screws to hold the automatic pump in place an used thinner gaskets. Later saws have one screw and a spring clip that wedges it in tight enough to get a good seal.

For the fuel line, a few wraps with Teflon thread tape will seal it up.

Mark

That's what I am missing, the spring clip. I have the one screw but no clip for that back.

 

[PogoInTheWoods]

So a PM850 is just a glorified SP80/81 with no points and better a/v unless it's a 81E. Not having done the IPL research, seems like what I'm reading would indicate the top ends are essentially the same with the exception of mounting points for the additional hardware configurations.

And a lot (if not most) 10 series cranks have the points cam on what I also understand to essentially be an interchangeable part in the series even though the part#'s vary from IPL to IPL. I believe you could also probably find many electronic ignition saws still using the points crank just to move them out of inventory while integrating the newer crank into production.

Just thinking out loud and may be all wet here...

 

[Gizzard]

Just thinking out loud and may be all wet here...

"Thinking out loud" is okay, seemed like Mac used that same idea a lot on assembly.