McCulloch Chain Saws

[Syncop8r]

They are less than thrilled. They always get super offended whenever I fire up a saw.

It takes a lot to impress a chicken.

 

[vinnywv]

Thats one of the funniest statements ive ever heard!! Lmao

 

[Syncop8r]

You could say you fell foul of them.

 

[northwest saws]

You could say you fell foul of them.

Oh man, lol. Yeah I definitely ruffled some feathers!

Sent from my SM-N970U using Tapatalk

 

[PogoInTheWoods]

Don't quit your day jobs anytime soon, fellas. LOL

 

[Alaskan Stihl]

Hello fellow Loggers! I just recently acquired a McCulloch Super 797 (model number indicates 66251?). I was able to locate a IPL sheet as well as a Clymers snippet regarding Service Manual (much thanks)…however, I am still on the hunt for a operators manual.

Unfortunately for me, this chainsaw has a stuck piston….good news is that it doesn’t appear to be scored (view from the exhaust port). I have it soaking with Marvel Mystery Oil via spark plug hole (I tried PB-Blaster…soaked for 12 hours….no luck). I will give the mystery oil soak for a couple days and see what gives next…

I read where the technique is to let it soak for a couple of days…then drain out the oil and apply heat (via heat Electrical Gun) to the head area and try to turn the crank with a ratchet wrench.

Question: Does anyone have any better suggestions or ideas of how to unstick the piston? *Note that I was told it was last running about 5+ years ago. More than likely, it is ring seized from setting too long…

ALSO: How the heck does the Decompression valve assembly work on this saw? I flipped the lever off of the clip and….well I am not sure exactly what it is suppose to do? Does it open the valve or something? Maybe mine is stuck? Dunno? Thoughts?

FINALLY: If anyone has a PDF of the Operators Manuals Manual for this…it would certainly make my day (been scouring the net… no such luck yet! HELP!

 

[Alaskan Stihl]

ALLLSOOOO: I have a McCulloch PM610. Yup, got it at the dump…. And got it running pretty darn good! Problem is, that it leaks bad oil like a sieve. When I set the saw down (say overnight), there is a large puddle in the morning. I read the threads that stated it was the ball check or something and I should cycle through some Marvel Mystery Oil through it to get things back in order. NOTE: that the manual pump works fine (no probelm…other than the button sticks in and I have to pull it out each time…..in which I ordered a spare and am going to swap it out….or file doen the plastic “shelf” that the clip rides on as I believe this is that problem resolve).
Back to th original issue…any other ideas to get it to stop leaking out oil? I unscrewed out the adjustment until it finally started “auto oiling”. But now I have a mess each morning. Is the oil pump itself shot? Thoughts?

 

[Maintenance supervisor]

Hello fellow Loggers! I just recently acquired a McCulloch Super 797 (model number indicates 66251?). I was able to locate a IPL sheet as well as a Clymers snippet regarding Service Manual (much thanks)…however, I am still on the hunt for a operators manual.

Unfortunately for me, this chainsaw has a stuck piston….good news is that it doesn’t appear to be scored (view from the exhaust port). I have it soaking with Marvel Mystery Oil via spark plug hole (I tried PB-Blaster…soaked for 12 hours….no luck). I will give the mystery oil soak for a couple days and see what gives next…

I read where the technique is to let it soak for a couple of days…then drain out the oil and apply heat (via heat Electrical Gun) to the head area and try to turn the crank with a ratchet wrench.

Question: Does anyone have any better suggestions or ideas of how to unstick the piston? *Note that I was told it was last running about 5+ years ago. More than likely, it is ring seized from setting too long…

ALSO: How the heck does the Decompression valve assembly work on this saw? I flipped the lever off of the clip and….well I am not sure exactly what it is suppose to do? Does it open the valve or something? Maybe mine is stuck? Dunno? Thoughts?

FINALLY: If anyone has a PDF of the Operators Manuals Manual for this…it would certainly make my day (been scouring the net… no such luck yet! HELP!

I personally like Sea Foam's product called DeepCreep , which I soak every possible port with then plastic bag it for a month, go back and try to rotate the flywheel by hand and repeat if necessary.

 

[Syncop8r]

ALLLSOOOO: I have a McCulloch PM610. Yup, got it at the dump…. And got it running pretty darn good! Problem is, that it leaks bad oil like a sieve. When I set the saw down (say overnight), there is a large puddle in the morning. I read the threads that stated it was the ball check or something and I should cycle through some Marvel Mystery Oil through it to get things back in order. NOTE: that the manual pump works fine (no probelm…other than the button sticks in and I have to pull it out each time…..in which I ordered a spare and am going to swap it out….or file doen the plastic “shelf” that the clip rides on as I believe this is that problem resolve).
Back to th original issue…any other ideas to get it to stop leaking out oil? I unscrewed out the adjustment until it finally started “auto oiling”. But now I have a mess each morning. Is the oil pump itself shot? Thoughts?

I have the exact same problem with mine.

 

[mogulmasher]

50/50 mix of tranny fluid and acetone may unstick that 797 too.

 

[PogoInTheWoods]

Ditto on the above -- and plenty of patience. It's not uncommon for the process to take days, if not a week or two in stubborn cases. What's possibly more common is piston or cylinder damage from excessive force being applied to the assembly before penetrants or lubricants have had a chance to be effective.

 

[fossil]

ALSO: How the heck does the Decompression valve assembly work on this saw? I flipped the lever off of the clip and….well I am not sure exactly what it is suppose to do? Does it open the valve or something? Maybe mine is stuck? Dunno? Thoughts?

The lever for the decomp holds the valve into the cylinder to seal it up. When it's released the valve is backed out..
You might want to check that it's not all carboned up.
It's located in the clutch side of the cylinder and is number 69 in figure 6, powerhead assembly on the IPL I have.

 

[rwoods]

ALLLSOOOO: I have a McCulloch PM610. Yup, got it at the dump…. And got it running pretty darn good! Problem is, that it leaks bad oil like a sieve. When I set the saw down (say overnight), there is a large puddle in the morning. I read the threads that stated it was the ball check or something and I should cycle through some Marvel Mystery Oil through it to get things back in order. NOTE: that the manual pump works fine (no probelm…other than the button sticks in and I have to pull it out each time…..in which I ordered a spare and am going to swap it out….or file doen the plastic “shelf” that the clip rides on as I believe this is that problem resolve).
Back to th original issue…any other ideas to get it to stop leaking out oil? I unscrewed out the adjustment until it finally started “auto oiling”. But now I have a mess each morning. Is the oil pump itself shot? Thoughts?

I have the exact same problem with mine.

Doc McHeimann in addition to his general practice specializes in ten series oil pumps. In his absence, I will repeat my experience with an 82cc Mac that spewed oil when shelved so much so that when the original owner want to buy it back I gladly agreed. He reported that he fixed it by simply turning the flow adjusting screw back in a bit. Possibly that would fix your problem too.

Ron

 

[heimannm]

I believe in this case it is the 600 Series McCulloch Pro Mac 610. If the oiler is pumping too much oil it can accumulate in the clutch cover and drip off when the saw is setting. The adjustment screw is right on top of the automatic oil pump, turning the screw clockwise will reduce the flow.



Mark

 

[heimannm]

I put this CP125 together from a box of parts sent home with me by Don AKA sawfun a few years ago. I took it back to the PNW GTG this year to turn it over to Don but unfortunately there was an undiagnosed problem. I discovered the issue a few weeks ago (the boot was not properly seated on the intake of the saw) and took it up to Baraboo, WI for the event up there last weekend. The cottonwood log was not much of a challenge for the saw so today I took it along on a large oak tree removal project I was helping my friend Erik with.

Erik was kind enough to let me fell the main trunk of tree and buck it into firewood lengths. I ran three or four tanks of fuel through the saw and it performed flawlessly. The 48" roller nose bar was just a bit too shorts in a couple of operations. I will also note that the temperatures were in the low 90's today.



It rained yesterday and overnight so the ground was a little soft...



Earlier in the day Erik was working from the bucket of his boom truck lifting off sections with his crane. Not just anyone can drop start a Double Eagle 80 hanging over the rim of a small bucket.



This stick weighed a little over 4,800 pounds.



900 pound cookies thanks to the CP125.



Mark

 

[rwoods]

Hard to beat that kind of fun, except maybe when it’s 30 to 40 degrees F.

Ron

 

[heimannm]

I wasn't completely happy with the way the chain was oiling on the CP125 while cutting yesterday. Before cutting it would keep the chain wet and pumping the manual oiler was easy enough. Once I started cutting the manual oiler was very hard to operate and the chain always looked rather dry. Today when I was cleaning up the saws I tried the manual oiler with the bar off and it worked quite easily and moved a lot of oil. Examining the bar more closely revealed that the only route for the oil from the bar pad to the groove in the bar was a very tiny internal slot cut between the two holes in the bar as the oiler in the bar pad lined up with the hole closer to the slot. The hole further from the slot is sealed on both side by the bar plates.



I remedied this situation by milling a slot between the holes to provide a better path for the oil to flow. It was pretty obvious that the tiny passageway in the bar was getting plugged with sawdust and preventing the oil from flowing from the bar pad to the groove in the bar.



When I put the bar and chain back on the saw and started it up the oil flow was greatly improved and the manual oiler worked very easily. I am looking forward to the next opportunity to run this saw in some big wood. I want to make sure it works properly before I hand it over to Don next year.......

Mark

 

[Jethro 2t sniffer]

Good job Mark as always

Tinman took to that 850 with a burr. Will see what she runs like. He showed every little bit nicely and think will be rather easy to have a go at with his video playing in the shed.



My 81 is getting due for a rebuild so I might attack it and maybe the muffler too. Perhaps even just blanking off the "box" and letting it vent straight out.

Only thing is I don't want to ruin that low down pull the 82s have

 

[Alaskan Stihl]

Back for more info.

Ok, here is another sidebar project I am working on. I acquired a Stihl MS290 that had obvious scarring on the piston rings (rings toast…piston scarred…low compression).

So. I ordered a Jug & Piston and was able to successfully dismantle the saw (first time ever with this sort of repair).

One of the key things I garnished off YouTube (other than the step by steps) was the comment to first determine what caused the seizure in the first place…to avoid it happening again. I conducted a pressure/vacuum test (passed). So I thought I was good to go with the seals!
Since this saw was given to me (another dump throwaway special) there is no way to absolutely know for sure what happened to it (best guess is someone didn’t mix their fuel).

I reached the end of the rainbow (all parts removed and getting ready to install the piston) when I noticed what appears to be damage to the seal (see pic). Correct me if I am wrong…but this is not normal right? My guess is that this damage let in air and leaned out the mixture causing ring/piston damage?

Any thoughts? Probably best to replace both seals right? Any tips or suggestions? I noticed on YouTube one of the bear traps was that the back bolt that hold the chain is actually loctighted in position and can be a can be a devil to remove? How about the flywheel etc? Will I need to purchase a puller?

 

[Alaskan Stihl]

Here is a helpful McCulloch Tip. On my PM610, I discover the Bar Adjustment Assembly was well used and “wobbly”. I purchased another one off of eBay and was able to remove the “Locknut” on the back of the unit with screwdriver and shaft nosed pinchers (albeit…it wasn’t super easy).
HOWEVER…when I tried to reinstall the replacement….what a nightmare! I couldn’t get the locknut squirreled back in there due to the “backplate” being in the way. After about an hour of frustration, it was becoming obvious that I was going to have to remove the clutch assembly (not knowing what that entailed? Maybe easy…? Maybe can of worms?). So then I could remove the backplate and install the bar adjustment assembly.
Suddenly, I realized I had a set of “Craftsman Angle Head Small Chrome Wrenches“. That bugger fit on there like a glove! I tightened and adjusted the locknut with ease.

I realize removi the clutch was probably the route to go…but knowing my luck, I would break something or a part would go flying etc