McCulloch Chain Saws

[Jasonrkba]

Mac 1-70 assembly. The cylinder top has an aluminum gasket. Do you apply anything like motoseal or just bolt it up?

 

[Marvin Booysen]

https://www.summitracing.com/parts/the-14260Internets help.

Those look great, but not sure they'd fit between the cylinder fins. The original sleeve is quite thin and fits tightly around the wire, but can move around though. The assembled wire/sleeve is a super tight fit between the cylinder fins as I recall.

Not too many hot rods or auto parts stores on the island of Sardenga I would guess...

I know I have a few models with the wire tucked into the cooling fins inside of the shroud without any kind of insulation. I don't run those saws a lot but the wires were always in good condition as I recall.

Mark

I know of some auto parts shops, but haven't encountered any hot rods around here
Thanks guys, considering also that it seems from the workshop manual that these sleeves were not necessarily installed on all models (they recommend it be installed if absent), I'm going to run it as is for now. Might check out that Stihl sleeve that Woodslasher mentioned, since I've got a dealer nearby.

 

[heimannm]

Jason - no sealants required.

Mark

 

[PogoInTheWoods]

I know of some auto parts shops, but haven't encountered any hot rods around here

If you're hell bent on insulating the plug wire, you may want to try an electrical contractor supplier (or even a hardware store) for plain old thermal mesh like found in appliances and other hi-temp applications. I went that route for the wiring on my fireplace insert blowers after the factory wiring melted and shorted to the frame. Can't remember the cost, but it was a lot cheaper than the race car stuff. Has held up for several years now. Just a thought...

 

[mogulmasher]

I posted a wanted ad, but haven't had any response. Figured some of you guys might not check classifieds. Anyone have a muffler cover for my 7-10 they'd part with? Running it like this makes an already loud saw really loud!

 

[Jethro 2t sniffer]

I posted a wanted ad, but haven't had any response. Figured some of you guys might not check classifieds. Anyone have a muffler cover for my 7-10 they'd part with? Running it like this makes an already loud saw really loud!View attachment 928642View attachment 928643

Looks perfect to me. I wear plugs aaand muffs when running the Mac's

 

[mogulmasher]

Haha no doubt I love the mcculloch national anthem....and I do wear muffs. However, I often run them in residential areas so would love to just tone it down a notch.

 

[Jethro 2t sniffer]

Haha no doubt I love the mcculloch national anthem....and I do wear muffs. However, I often run them in residential areas so would love to just tone it down a notch.

Not sure there's really much better to be honest though

 

[Woodslasher]

Haha no doubt I love the mcculloch national anthem....and I do wear muffs. However, I often run them in residential areas so would love to just tone it down a notch.

I thought that's what off-brands were for? I might have a spare muff cover hanging around, which version are you looking for? I think I have a spare "straight-shot" cover hanging around, which I would be willing to trade, or I could put it on my 5-10 and send you a #2-type cover. If you want option one, I can't help ya. I'd need to trade covers with you as I may need the "spare" cover for my SP60, in case its current muffler isn't quite the powerhouse I hope it is.
#1:

or #2:

My SP60 muffler: As I said elsewhere, "Does it look hokey? Yes. Does it seem stupid? Yes. Will I still run it like this for a little, then try a normal cover and see which feels mo' powerful? Yes."

 

[Jethro 2t sniffer]

I thought that's what off-brands were for? I might have a spare muff cover hanging around, which version are you looking for? I think I have a spare "straight-shot" cover hanging around, which I would be willing to trade, or I could put it on my 5-10 and send you a #2-type cover. If you want option one, I can't help ya. I'd need to trade covers with you as I may need the "spare" cover for my SP60, in case its current muffler isn't quite the powerhouse I hope it is.
#1:

or #2:

My SP60 muffler: As I said elsewhere, "Does it look hokey? Yes. Does it seem stupid? Yes. Will I still run it like this for a little, then try a normal cover and see which feels mo' powerful? Yes."

Yeah they stick out quite far on a left pull start saw

 

[mogulmasher]

I think option #1 is what it had on it.

And yes a couple of my off brands are a bit quieter, others are just as loud as a Mac.

 

[Alaskan Stihl]

Greetings: Forgive me in advanced if I am in the wrong forum location (I am still confused in maneuvering my around in here).
I recently acquired a McCulloch Super 797. I got it in a purchase deal with the understanding that the Chainsaw was previously running, however It has been setting for several years and the piston is now seized. I removed the muffler and can see that the piston looks fair (no obvious scars) however it is too far up to get a look at the rings.
So far, I have filled the spark plug hole with PB-blaster for about 10+ days and tried to turn it over with a socket & breaker bar on the flywheel nut (No luck). Next, I emptied out the PB-Blaster and filled it with Marvel Mystery Oil and let set another 14 days and tried it again (no luck). Finally, I decided to go with a thinner solution, and emptied out the Marvel Oil and sprayed in some Kroil. It has been sitting for about a week now. I tried it again (no luck).

I am a little concerned that the threads on the nut on the Flywheel Nut they are a little worn and don’t want to strip them out. I plan on replacing it (if I can find a replacement). Hopefully I can get one at our local Stihl Shop (or Home Depot?). Who knows?
Anyway, I am not sure what my next step should be?
#1. Let it soak for another few weeks and keep trying?
#2. Try heating the Cylinder with a Heat Gun the next time I try to free it up?
#3. Use a small impact gun the next time to try and free it up?
#4. Start dismantling and go from there?

All I have to work from is a Illustrated Parts List and a excerpt from the Clymer Book (much thanks to the person that got me that far). Obviously, if there is a copy of an actual McCulloch Service Manual out there for this saw, that I could get my hands on…that would be a huge plus!
Attached is a couple pics of my project. I have limited Mechanical Skills…but can get by in a pinch.

Does anyone have any other suggestions or thoughts they can offer me on this project? Any more tips?
Thanks a bunch!

 

[Syncop8r]

Yes you're in the right place.

Now, I remember someone trying to free a seized piston recently, I think heat was the winner in the end.
Was it on this thread? Or in a YouTube video? Tinman? Clint?

I think you have already tried the Beg For Manuals thread?

 

[Alaskan Stihl]

Syncop8r: Correct, I originally posted in the Beg for Manuals thread and was able to get the IPL & Clymer Manual.

I think I also posted my “Piston Seized Project” in that thread as well (Beg For Manuals)…but figured that I should have probably posted my project in this McCulloch Site?
Anyway, I would be curious on how the “Heat Trick” worked out (as you mention)? I have a pretty good quality Heat Gun (for shrink wrap Electrical Fittings) but am gunshy on how hot I should get the cylinder? I suppose a Heat Gun would probably not overheat anything…even on its highest setting? I am leery about using a propane torch on it…probably not a good idea….
As mentioned, I am definitely not a small engine mechanic and any tips or secret mechanical advice would be greatly appreciated.

 

[Maintenance supervisor]

I like Deep Creep by Seafoam for soaking a stuck cylinder, often letting it soak for a month.

 

[Alaskan Stihl]

Maint. Supv: Thank you for the suggestion, I will have to try that next and see what happens. Obviously, this is also going to be a test of my patience as well (haha).
Here is another head scratcher as well. I removed the Carburetor and was hoping that I could also put some fluid through the intake…however, in this chainsaw, the intake is peculiarly shaped in that there is a “vertical lower intake passageway” that appears to be blocked off at the bottom. I read where those might be “Reed Valves” or something? Who knows? Difficult to see in there. Anyway, I was wondering if it would be beneficial to spray something down the intake passageway…?

 

[vinnywv]

Yes those are reed valves. To be effective theyd need removed. Im sure some spray would get by but if removed it would be best

 

[Alaskan Stihl]

vinnywv: I was kind of thinking that is what those were. Obviously, to get those out of the way so I could get some fluid in there would probably mean that I would already be in my way to full disassembly? I will have to do some research I suppose (very limited service support resources with these old saws I am finding out). I guess once I start dismantling…it will all make sense….more or less.

 

[heimannm]

If the piston is covering the ports, make a fitting from an old spark plug and a grease zerk fitting. The grease gun will provide over 2,000 PSI and will most likely start the piston moving. I have successfully removed stuck pistons from a BP-1 and PM555 most recently using that technique.





The crankshaft threads for the flywheel side are 7/16-20. Not a size commonly used today but the nut is still available from better fastener vendors.

Mark

 

[heimannm]

Additional thoughts - I had a stuck piston ring on a BP-1 piston (after getting the piston out starting with the grease gun technique). Heating with an electric heat gun and soaking (Seafoam) did not free it up, heating with a propane torch then quenching in the Seafoam did eventually get it free.



Mark