MCCULLOCH The official McCulloch thread

[MNMacGuy]

Something I've noticed on the 600 series mufflers is that people tear the screens off.Could someone explain why folks do that? Do the screens restrict the exhaust somehow? I know that if you're cutting on federal lands & some state lands too,those spark arrestor screens must be on the saw or you're not allowed to cut.

Several of my 600 series saws have had muffler screens plugged with carbon and sticky oily sludge. With a little effort a wire brush and degreaser can clean them up pretty well but most people apparently just tear the screens out. I've found many missing screens as well. When the muffler is restricted you can get poor running and hard starting issues.

 

[edju1958]

Several of my 600 series saws have had muffler screens plugged with carbon and sticky oily sludge. With a little effort a wire brush and degreaser can clean them up pretty well but most people apparently just tear the screens out. I've found many missing screens as well. When the muffler is restricted you can get poor running and hard starting issues.

Back when these saws first came out I'm sure the owners were using 30 W oil mixed with gas as their 2 stroke fuel.I've seen many,many saws that were clogged up using that old mixture.Even the McCulloch 2 stroke oil was just a glorified 40W oil with some additives.Now with modern oils there shouldn't be any more screen clogging,unlesss folks are mixing at 10:1 ratio

 

[Al Smith]

If you are talking about the 610-650 series by that time period most people were using some form of mix oil not sae 30wt .If you look at how they exit,down out of the cylinder on a sharp bend then directed upwards on the exit with the screen the last thing it passes through .Not the best exhaust systems ever made .Combine that fact with the fact the impulse bar lube pumps often leaked into the crankcase and gummed up the screens .That's why they removed the screens which at least in Ohio is not illeagal plus we have no chainsaw police I'm aware of .

 

[edju1958]

If you are talking about the 610-650 series by that time period most people were using some form of mix oil not sae 30wt .If you look at how they exit,down out of the cylinder on a sharp bend then directed upwards on the exit with the screen the last thing it passes through .Not the best exhaust systems ever made .Combine that fact with the fact the impulse bar lube pumps often leaked into the crankcase and gummed up the screens .That's why they removed the screens which at least in Ohio is not illeagal plus we have no chainsaw police I'm aware of .

Al,if you'll read the first few words of my last post,I said "when those saws first came out",which was around 1984,the modern oils were just starting to come out.Of course there were die hard hardheads that didn't trust the new oils,so they continued to use the SAE30W.
As for chainsaw police inspecting your saw - try going into federal land without a spark arrestor & tell me how you make out.I also said SOME states require a spark arrestor when cutting on state lands.

 

[edju1958]

Today I had something happen that has never happened before.I was changing out the clutch on a 610 & lubed the bearing.I had a recoil rope in the plug hole to use as a piston stop & the piston cut the rope.I had to pull the saw down to the engine & take the engine apart to get the rope out of the cylinder.I know that I'll need to use a sealant on the oil tank,but do I need to use sealant on putting the engine back together?Can I use Moto-Seal?

 

[heimannm]

I have used Threebond, Indian Head Shellac, and currently use Dirko HT (easier to clean up). You do need to use something on the crankcase halves, I include a thin layer in the bearing pockets as well.

Mark

 

[JKNW]

Today I had something happen that has never happened before.I was changing out the clutch on a 610 & lubed the bearing.I had a recoil rope in the plug hole to use as a piston stop & the piston cut the rope.I had to pull the saw down to the engine & take the engine apart to get the rope out of the cylinder.I know that I'll need to use a sealant on the oil tank,but do I need to use sealant on putting the engine back together?Can I use Moto-Seal?

I wouldn't hesitate to use Motoseal if that's what you have, that's what I use on the newer clamshell saws when I put them back together.

 

[JKNW]

So i got to tinkering around with the 1-42 in hopes of putting it in some wood this weekend. Turns out, the saw has been converted to an Oregon rim sprocket and currently has a 3/8 rim. Not a problem on its own, but I also assumed the saw and the random eBay bar and chain I bought was .404 (it eyballed bigger than 3/8 but smaller than the 1/2" on my Super 33). I figured this out of course by buying a fresh loop of .404 then discovering that it wouldn't budge once adjusted.

 

[cinci5]

I wouldn't hesitate to use Motoseal if that's what you have, that's what I use on the newer clamshell saws when I put them back together.

I too use Motoseal, I used to use Dirko but found that it tends to seperate and breakdown. A thin layer of motoseal seems best not thin bead. McCulloch ash-less oil came out in the early 70's I used to use it in my Polaris race sled. It was a great oil. My father who was a McCulloch distributor for New York swore by it.

 

[Al Smith]

Here we go the history of mix oil .As for the Mac pm 610 etc it was earlier than 1984 . According to Mike Acres it first hit the market in 1978 .The first of that model which I still have was prior to 1980 and it still runs fine . That said even in '78 there were mix oils or at least they were used in this area .Prior to that it was not uncommon to use outboard motor mixed fuel often at 16 to one .Now of course SAE 30 could have been used by some .I only did so very rarely .They smoked a little bit which was not a big deal in warm weather,you could cut wood and fog for mosquitoes at the same time .
I might further add to this the first new saw I ever bought was an orange version of a Poulan S25 da in 1974-75 and the dealer threw in a jug of mix oil for the ratio of 32 to one $139.95 out the door.I still own that one also 50 years old and still runs just fine .

 

[Dream]

I have used Threebond, Indian Head Shellac, and currently use Dirko HT (easier to clean up). You do need to use something on the crankcase halves, I include a thin layer in the bearing pockets as well.

Mark

+1 to recommend Dirko HT.
I have used Motoseal before.
Does fine if theres no danger of the parts moving or heat cycle expansion/contraction. I have had ONE instance on a riser base to lower cradle that leaked on a different color saw. Motoseal is semi-hardening if I recall correctly.
Used Dirko the second time, and no issues so far.

 

[edju1958]

I was kinda leary about using the MotoSeal as Mark had recopmmended others.I've used Permatex blue on oil tank to engine assembly,but never on the engine halves even though it's rated up to 600*.I figure if the engine gets that hot it's most likely toast.I also noticed that Mac only used a skim coat of clear silicone sealant on the oil tank & nothing on the engine at all.Thoughts on this?

 

[heimannm]

They also used the clear silicone on the crankcase on later saws. It could be it was a very thin layer on your saw, most of the time you could see a little squeeze out at the seam and around the bearing pockets. You won't get a tight seal without some kind of dope in there.

Older saws like the the SP models used something more like a Permatex (hardening) product.

Mark

 

[Dream]

I was kinda leary about using the MotoSeal as Mark had recopmmended others.I've used Permatex blue on oil tank to engine assembly,but never on the engine halves even though it's rated up to 600*.I figure if the engine gets that hot it's most likely toast.I also noticed that Mac only used a skim coat of clear silicone sealant on the oil tank & nothing on the engine at all.Thoughts on this?

The gasoline resistance is a factor to be considered.
Motoseal and the like are all gasoline resistant.
I'm not 100% positive that Dirko is. I would have to read up on it a bit more.
I have heard from a couple of guys that build saws for a living, and they havent had any issues with Dirko failing from fuel interaction.
Case sealants are almost as touchy of a topic as two stroke oils, so I'm not saying what I choose to use is the best. I'm just relaying my personal experience.
Ive succesfully used Motoseal to seal a leaky tank gasket more than once, so I know for a fact that it works for me.
Should I have replaced it with a new EPDM gasket? Yes.
Did I have one? No.
Did I want to wait? No.
Would it have stopped leaking on its own once the cork gasket got saturated with fuel mix after sitting dry for many years?
Most-likely. Sometimes patience is the BEST cure.
Just did that with my SP81.
It was weeping fuel at the tank gasket.
I filled it with fuel, sat it on the back work table, and left for work out of town for a week.
Came home and the shop smelled like gas. There was a noticeable stain/wet area around the tank halves.
Refilled it and forgot about it for another week.
Next weekend, no fuel smell in the shop. Outside of tank was dry and fuel level had held.

 

[cinci5]

I still have and use Dirko, been using it for years. The breakdown issues were on snowblower repairs for some reason. Mostly carb sealing. I had a small side hustle doing repairs for landscapers and arborists. Landscapers would plow in winter and some have 2 cycle throwers for sidewalks. Have since backed off since many hand surgery's. Also cut many many trees down for people for the firewood. Only doing stuff for one large grass cutting company now. Repairing goes way back to the late 60's in my dad's shop.

Just can't stop tinkering.


And that's my story and I'm sticking to it.

 

[edju1958]

I guess everything happens for a reason,i.e.my 610 having to be torn down to get the broken recoil rope out of the cylinder.If it were not for having to tear down the engine I would've never learned that I have to use sealant on the engine halves,& subsequently I found out why my 610 build I did last summer acts like it has an air leak even with new seals.(I didn't seal the engine halves on that engine when I split it to replace the seals) I also have a 10-10 & a Super 2-10 with the same condition.
Other saw makers (Homelite,Remington,etc.) used gaskets on their engine halves,I'm wondering why McCulloch didn't do the same?

 

[Al Smith]

The use of sealants becomes a point of debate almost like the great never ending war of the oils .In the days of the Model T Fords Permatex in some form has been around plus Indian head gasket shellac .It obviously worked but has been questioned how well with ethanol types of gasoline .
Modern automotive engines have taken to Locktite 5900 which is a form of silcone in place of most gaskets which works else they would leak oil like a 1940's Harley Davidson .
I say use whatever you want because it won't take very before you'll know .I'm a gasket guy myself if applicable .Regarding the old McCullochs I think they used Indian Head shellac .Caterpiller used Permatex number one which makes it real difficult to remove the parts,takes a pry bar .A lot of difference between a chainsaw and a bull dozer ,larger tools as well .

 

[heimannm]

Dirko HT is not resistant to gasoline, in fact you can use straight gasoline or mixed fuel to soften it up when it comes time to clean up parts assembled with it.

Since Stihl uses it on all of their models with clamshell crankcases, I'm guessing it is good for our applications as well. I have used it on quite a few saws (I am on my third or fourth tube by now) and so far I have not had any failures that I am aware of. It would not be a good choice for a fuel tank leak; I have used Threebond 1184 in that application with good success, but best wishes to anyone that has to try and take it apart and clean it off in the future.

If I recall, acetone will soften/loosen the Threebond to make removal easier but I haven't had to try it recently.

Mark

 

[edju1958]

Today was somewhat of a nightmare.It started off with a 610 recoil that fought me tooth & nail,but finally got it together.
Then it was on to putting the 610 engine & oil tank back on the saw.I used Permatex blue which when I bought it I thought it was a silicone sealant,but not the case.I got the saw all back together (engine-wise) & took a lunch break.While having my lunch,I decided to read the Permatex packaging & found this sealant was "not good for the use on head gaskets,or gasoline resistant".So,I pulled it back apart & removerd the Permatex.I then applied a coat of MotoSeal & put it back together again.While tightening the oil tank bolts I remembered that I only did the sealant on one half of the engine.So apart again & re-seal again.While apart the last time I figured I'd better put a new seal on the PTO side.If this saw has an air leak I swear I'll shoot it.

 

[edju1958]

I've noticed on the 600 series recoils that there were at least 3 different styles of how the pulley is mounted.On one of my 610s it has a step bolt that goes up through a plastic shaft & the pulley is held on with a jam nut.On another 610 it has a step bolt going up through the plastic shaft & the pulley is held on with a screw & washer.On yet another 610 there's no step bolt ( the plastic shaft isn't even drilled for it) & the pulley is held on with a screw & washer.I do question the integrity of the plastic shaft alone over time.