McCulloch Chain Saws

[edju1958]

I'd check the drum/bearing for slop. Then again, some saws I've run just "ping" for no apparent reason and others of the same model don't.

I put a new drum & rim on it right from the start.The bearing is good & I lubed it.This dinging is not normal.I've got several older 10-10s & NONE of them make a single sound with the clutch.

 

[Maintenance supervisor]

Ive got a few that ring also.

 

[MacAttack]

I put a different clutch on the 10-10 & got the same resuilts - ring like a dinner bell.I've exhausted my options,I even tried another recoil/cover.Time to strip it down & take it out back for target practice unless someone here can tell me why it's doing this.I even looked at the IPL to make sure I hadfn't deleted anything accidentally.

Meanwhile,I started working on another 10-10,this one is a LH start (normal).It needed a fuel tank cover to start & I found one with the screws it needed to put it on the saw.The gasket looked good,so I just put a small bead of Yamabond on it & tightened it down.The recoil was missing a couple screws,so I robbed them off another 10-10 LH start.I also found a good fuel line that I gave a couple wraps of Teflon tape to ensure no leaks.I'll need to rob a couple bar stud nuts from the old 10-10 that's obviously possessed.Next on the agenda is to put a carb on the saw & then fabricate another air filter bracket.

This may or may not have anything to do with it and I might have missed this but is there a washer on the crank behind the clutch drum?
But some of my smaller Macs make that noise and I just ignore it.

 

[Alaskan Stihl]

Quick Question for any McCulloch Mechs out there in regards to a McCulloch Super 797:
#1. Does anyone known what the compression range is suppose to be on this to pass?
#2. (Bear with me if this is a stupid question):
History: I purchased a Compression Tester today and hooked it up to the saw. Problem is, that I am not sure if the decompression valve is working or not (To be honest…I am a little confused on how it operates since I lack an Operators Manual). I get what it does though…but have never used one. As seen in the picture, is this where it is suppose to be when testing for compression? I am assuming that the lever is supposed to be “Up” (Start Arrow) to decompress and once it starts…you click it “down” (Run Arrow) to lock it in place for full compression? Problem is, I tried both settings and can’t tell any differences (extremely tough to pull and recoil spring won’t retract properly.
So…here is the question(s):
First: Am I correct on the decompressing settings?
Second: For the purposes of getting an accurate compression test…can I remove the recoil cover and put a drill-socket on the flywheel to turn it over a few times (and fix the recoil spring issue later..)????
Thanks Everyone/Anyone…

 

[MacAttack]

I put a new drum & rim on it right from the start.The bearing is good & I lubed it.This dinging is not normal.I've got several older 10-10s & NONE of them make a single sound with the clutch.

Is there any chance the crank has a slight bend / runout on the clutch end?

 

[PogoInTheWoods]

What I know (unless the seller BS’d me) is that it used to run…

They all did. LOL

I tried both settings and can’t tell any differences (extremely tough to pull and recoil spring won’t retract properly.

can I remove the recoil cover and put a drill-socket on the flywheel to turn it over a few times

You are likely still fighting the residual effects of the piston being stuck..., and tempting fate by continuing to do so having no idea what's happening in the bottom end of the saw except that it's probably full of solvent and who knows what else -- which can also provide inaccurate compression readings and will make it more difficult to pull over anyway.

And yes, I would remove the starter/clutch assembly, the top/intake assembly, the flywheel/ignition, the cylinder, the crank...

May not be what you want to hear, but it's what most here would do..., especially with a Super797.

 

[Maintenance supervisor]

Quick Question for any McCulloch Mechs out there in regards to a McCulloch Super 797:
#1. Does anyone known what the compression range is suppose to be on this to pass?
#2. (Bear with me if this is a stupid question):
History: I purchased a Compression Tester today and hooked it up to the saw. Problem is, that I am not sure if the decompression valve is working or not (To be honest…I am a little confused on how it operates since I lack an Operators Manual). I get what it does though…but have never used one. As seen in the picture, is this where it is suppose to be when testing for compression? I am assuming that the lever is supposed to be “Up” (Start Arrow) to decompress and once it starts…you click it “down” (Run Arrow) to lock it in place for full compression? Problem is, I tried both settings and can’t tell any differences (extremely tough to pull and recoil spring won’t retract properly.
So…here is the question(s):
First: Am I correct on the decompressing settings?
Second: For the purposes of getting an accurate compression test…can I remove the recoil cover and put a drill-socket on the flywheel to turn it over a few times (and fix the recoil spring issue later..)????
Thanks Everyone/Anyone…

That thing is filthy, you better sell it to me and save yourself from the terrible thing!

 

[vinnywv]

Quick Question for any McCulloch Mechs out there in regards to a McCulloch Super 797:
#1. Does anyone known what the compression range is suppose to be on this to pass?
#2. (Bear with me if this is a stupid question):
History: I purchased a Compression Tester today and hooked it up to the saw. Problem is, that I am not sure if the decompression valve is working or not (To be honest…I am a little confused on how it operates since I lack an Operators Manual). I get what it does though…but have never used one. As seen in the picture, is this where it is suppose to be when testing for compression? I am assuming that the lever is supposed to be “Up” (Start Arrow) to decompress and once it starts…you click it “down” (Run Arrow) to lock it in place for full compression? Problem is, I tried both settings and can’t tell any differences (extremely tough to pull and recoil spring won’t retract properly.
So…here is the question(s):
First: Am I correct on the decompressing settings?
Second: For the purposes of getting an accurate compression test…can I remove the recoil cover and put a drill-socket on the flywheel to turn it over a few times (and fix the recoil spring issue later..)????
Thanks Everyone/Anyone…

A few things. Yes you are correct, start is to decompress, run will close it off.
Since you have it that far i would take that little rod out and make sure the passage into the cylinder is not plugged with carbon. My 6-10 is made very similiarly and it was plugged up. I used a drill bit and my fingers only to drill it out. Clean that rod up so it moves freely and then test it. However.....i had the engine apart when i did that so no carbon got.into the cylinder area. Sure fire way to score it up with a hard piece of carbon. But just pull that rod out all the way and pull it over, you should feel pressure coming out of the little hole if.its open. If not then its plugged up giving you a good cause for the symotoms

 

[heimannm]

When you get to that point, the DSP should be locked in the "Run" position in order to get an accurate compression reading. I would be careful about using a drill and socket to spin it over from the clutch side as that will have a keyed clutch and they are not happy if you overtighten them. If you must spin it over with a drill, do it from the flywheel side.

150 PSI would be pretty good, it will still run, albeit with some reduced pep down around 100 to 110 PSI.

Mark

 

[edju1958]

Is there any chance the crank has a slight bend / runout on the clutch end?

To answer your 1st question - yes,there's a washer behind the clutch drum.As to t having a bent crank,who knows.

 

[edju1958]

I just can't win to go to hell.I put a carb on the 2nd 10-10,some jackass had straightened out the little crook on the end of the choke rod.Putting that little bend back in that rod is not easy,I've had them break trying to bend them,but I did manage to get it almost perfect.I put fuel in the tank & of course it had to leak.The saw would barely start & it ran so rich it couldn't throttle up.I pressure tested the carb & it had a very slight leakdown,so slight that it was barely noticeable.I'm done playing with the SDC2,I'll put a new SDC37 on & I'll have to pull the tank cover off & that'll get a different tank cover with a buna square O ring material as a gasket.

 

[Alaskan Stihl]

Thanks all for the tips. I guess I am going to go ahead and break it down and check all the internals first (clean everything up etc).

wish me luck !!

 

[PogoInTheWoods]

Glad to hear it. You are definitely in the right place for assistance from some of the greatest McCulloch people anywhere. Not that everyone is fortunate enough to own a 797, but most know their way around the older Macs enough to provide solid advice on many aspects of what you'll be getting into.

Good luck. But patience, common sense, and continuing to ask questions will probably get you a lot farther!

 

[Alaskan Stihl]

Pogointhewoods: Actually, as my first major mechanical venture, I just successfully completed overhauling a Stihl MS-290 (new piston, cylinder, seals, sprocket, carburetor oil pump bundle). Although there were hiccups along the way, it now starts right up and runs like a Stihl! Actually, it starts easier than my other MS-290 (one I purchased a few years back).
So, this McCulloch will be #2 tear down. The big difference is that I had a couple YouTube Videos to follow along with in regards to the Stihl…there isn’t crappola online in regards to the McCulloch (and the documents I have to work off of is an IPL & Clymer Service Manual Snippet). The big question will be: Are Gaskets/Seals etc available?

Any tips or suggestions are more than welcome (examples are: “Be sure to remove this…before that…or you will break the other”…or, “watch out for that Spring that will go flying”. etc)

I read where these cylinders can be bored you to .030 over? Can they be sleeved I wonder (just in case there is anything really bad with the cylinder)?

 

[Syncop8r]

So, this McCulloch will be #2 tear down. The big difference is that I had a couple YouTube Videos to follow along with in regards to the Stihl…there isn’t crappola online in regards to the McCulloch.

Sounds like you need to make a video of your tear down to help the next people out.

 

[Syncop8r]

I started sharpening my 2-10 and wasn't liking the results. Is this safety chain? Semi-chisel?
I finished one side and noticed something when I got to the last tooth...

Oh well, a good excuse to take it off and replace the 16" bar with a 20" one that I got that came with a sharpened chain.

 

[Woodslasher]

That's old Oregon semi-chisel chain, idk if those rakers have a specific name but I've seen them on lots of old 3/8 Oregon chain.

 

[PogoInTheWoods]

Just poke that thing outta there and replace it with a new link. Shouldn't be a tooth there anyway.

Actually, as my first major mechanical venture, I just successfully completed overhauling a Stihl MS-290

Ah, yes. I recall the wrath suffered by bringing up the 'off brand' subject within the sanctuary of all things yellow and black. LOL

The 797 will definitely be a greater challenge, but also much more worthwhile and gratifying. Searching specific McCulloch subjects both within the forum and with Google can be very productive. You will most likely encounter expert level results from Heimannm and others. 'Mac 797 Rebuild' should keep you reading for awhile.

And while it may be tempting to join every McCulloch forum and FB discussion out there, that can also become more of a distraction than providing the clarity you're probably searching for. The information is the important part, not necessarily the discussion about it. Lots of guys frequent multiple forums, but you're in the right place here for what you're about to embark on. There's more than enough info and expertise to help you along. Parts can be a challenge at times, but usually seem to turn up sooner or later. Gaskets, carb kits, bearings, seals..., most can be found fairly easily. Not always cheap, but findable. You need to find out what the saw requires before worrying about anything else.

The IPL and searching are your best friends right now..., next to time and adequate space to lay things out and good light! LOL

Keep it fun and enjoy the journey. Now drain the fuel and oil if it still has any in it (and whatever else may start dribbling out the exhaust port) and start tearin' that rascal down. Just go slow and don't force things.

 

[Jethro 2t sniffer]

I started sharpening my 2-10 and wasn't liking the results. Is this safety chain? Semi-chisel?
I finished one side and noticed something when I got to the last tooth...View attachment 931718

Oh well, a good excuse to take it off and replace the 16" bar with a 20" one that I got that came with a sharpened chain.

Yes thats a safety chain. Go down to the saw shop n get a joiner n hammer over the ends or give them 10 bucks to join it

I cut all the safety bumpers off mine but really no need to

 

[edju1958]

I'm getting closer on the 2nd 10-10 nrunning.I changed out the tank cover that had the cork gasket in it for one that has the buna square O ring in it that I did last yr.I tried starting it again after some carb leaning adjustments & it still wants to run rich.I think either the metering diaphragm is not hooked in the lever,or the lever is set a bit too high.I'll pull the carb tomorrow,but don't know if I'll have time to take it apart & reinstall.I'm getting there with this one.

Meanwhile I started on 10-10 #3.I pulled the tank handle off & had plans to put anotherr one on that has the flat air filter,but the manual; oiler won't work.I took the "auto oiler" out to make sure it wasn't filled up with crud.I've never seen an auto oiler like this one.There's no piston in it that works off impulse from the engine.I'm assuming it works off the impulse from the engine,but I have no idea as to how.