McCulloch Chain Saws

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I have a 10-10S on the bench. 140psi compression, has spark, will not pop. Filthy saw. It has had a hard life. I am going into it. Starting with coil and lamination gap. Any guesses? Lets make a game out of it so to speak. I will ship the FIRST correct diagnose a new style electronic 10 series coil. So let's play a game. Each person gets one question that I will answer as I go.

Issues so far:

Has spark will not pop.
Leaks fuel at gas line pass through tank.
Tank half seal leaks.
Though compression tested good, turns easy by hand.
after squirting fuel in plug hole can easily turn saw by hand via flywheel with plug in Decomp out.

Copy this in reply with questions and guesses.
Lets have fun and Good Luck!
 
I have a 10-10S on the bench. 140psi compression, has spark, will not pop. Filthy saw. It has had a hard life. I am going into it. Starting with coil and lamination gap. Any guesses? Lets make a game out of it so to speak. I will ship the FIRST correct diagnose a new style electronic 10 series coil. So let's play a game. Each person gets one question that I will answer as I go.

Issues so far:

Has spark will not pop.
Leaks fuel at gas line pass through tank.
Tank half seal leaks.
Though compression tested good, turns easy by hand.
after squirting fuel in plug hole can easily turn saw by hand via flywheel with plug in Decomp out.

Copy this in reply with questions and guesses.
Lets have fun and Good Luck!
Flywheel key is sheared.
 
Hmmmm... I have seen videos (and perhaps posts on here) about adjusting the timing... suggesting it perhaps can just be 'out'? 🤔
You can adjust timing/dwell of points ignition by clocking the opening of them.
The only way to do it with electric ignition is to file the flywheel key ,thereby moving the ignition event.
 
You can adjust timing/dwell of points ignition by clocking the opening of them.
The only way to do it with electric ignition is to file the flywheel key ,thereby moving the ignition event.
And filing the woodruff key is tricky, and flirting with trouble. Best thing ever happened to me was I got through my "Hot Rodding" phase before I started wrenching on saws lol. Stock is good enough on the Macs. The were already engineered ahead of their time.
 
North East Tennessee MAC Report

Still getting a bit of rain in North East Tennessee so temperatures have not been too hot. Mostly tractor work today.

I was asked to cut up a large pecan that had fallen as a result of wet ground and the wind. I decided to use my 700 now that it has a fresh intact crankcase.

Look really closely and you'll see the 700 sitting high. I had a close up, but it didn't format properly according to MS though it looks fine on my cellphone.
IMG_3520.JPG

As you might expect the tree tried to standup after I got most of the weight off of it. Only had a 20" bar so I had to use an off brand to cut out the center for the final fall.
IMG_3524.JPG

Two large loads to the woodlot, leaving only two small piles and two heavy logs for another day.
IMG_3527.JPG

The smaller of the two logs weighs over 3300 pounds which is about 1000 pounds over my tractor's capacity; I didn't calculate the large log's weight. I could lift the little one about 6"; I couldn't lift the big one an inch. I thought pecan might be worth enough to try to sell it, but nope, so I will be cutting these in half so I can load them.
IMG_3528.JPG

Landowner was pleased with the result.
IMG_3526.JPG

At the moment, it looks like there will be little falling for Blind Squirrel Falling this season. Hopefully, a two-man job will come along so Brian can put his MACs to work.

Be safe,

Ron
 
I had a friend stop by the other day to put a new head gasket on my Sears lawn tractor & he brought his 17 yr.old son along.His son is a wiz at small engines & somehow he mentioned that he had a mini mac 1 all torn apart.I told him that I had a couple of mini macs that he could have if he wanted them.I dug them out & found that one had seized due to the plug missing from it,so I poured a 50/50 mix of acetone & ATF in the plug hole & let it set till this afternoon.I put a breaker bar & socket on the clutch nut & applied gentle pressure & it broke free. Now if I could only figure out why the recoil skips on both saws.
 
As many know, I basically parked my 700 a few years ago due to hand issues with the vibrations. I could barely do one tank before I would have to quit. Well, we came to an understanding through heavy gloves and intermittent use - cut a little, tractor a little. I had some hand cramping towards the end of the day but no numbness or tingling.

Ron
 
Thats right jethro, i have done some silly parts swapping with the 70cc saws. Ive put together many parts from different saws to make one or 2. Took a 7-10 engine and made a cp70, the took that apart and put that engine into a g70, then took it back apart and used bunches of stuff to build the super pro G70 antivibe gear drive...which runs and cuts just wonderful. So to add my 2 cents into the crankshaft comments. Mac used whatever they had. Ive run across keyed and no key 70cc stuff. Both right and left hand threaded. I got a crankshaft for a 5-10g of mark that had no keyway in it and it was also right hand threaded??? We both scratched our head over that one. Had to have a machinist pin that one for the keyed clutch and starting. Lots of different porting and transferrs out there also. Nothing would be too surprising based on the info gathered by people.

Ive been away from saws all summer so apologies for not commenting. Ive only worked ona few saws this year. My old truck has taken over life for the summer. Im stoked to say im driving it anytime i want to now. It seemed no different than a saw, just bigger. This was my first vehicle ever worked on. But ive also had a first saw ever worked on at one point. Ill get some pictures when i get home today...at work now. Ill attach a couple here of the day i got it home to driving it out the garage. Resized_20230602_123039.jpegResized_20230602_123010.jpegResized_20230602_123030.jpegResized_20230629_151106.jpegIMG_2994(1).jpg
 
Its nice to see some new names on the board also. Welcome gentlemen. I also got a new log splitter this year. The old one was 20 yrs old and worked fine but i was looking for a few more features and efficiency so i sold my old one to a young coworker and got us a wolfridge splitter! No more lifting heavy peices very often here. Im not getting younger. Also a 6 way wedge instead of 1. Electric start was a bonus and auto cycle was a must. Me and the little woman are gonna be spoiled firewood splitters till i cant split no more. Ive not used it yet so im anxious to test it out. It had a long lead time so we ordered it pretty early spring and it arrived late june. Ill let ya all know how it performs. Should be running macs and splitting here in a few weeks or less. Really missed tinkering on them. A guy looked at my screen saver at work and asked why i like macs so much....my response was.....fun to use, tons of torque and loud and loud and did i mention wake the neighbors loud!! Lol. Have a good day.
 
As many know, I basically parked my 700 a few years ago due to hand issues with the vibrations. I could barely do one tank before I would have to quit. Well, we came to an understanding through heavy gloves and intermittent use - cut a little, tractor a little. I had some hand cramping towards the end of the day but no numbness or tingling.

Ron
What do think contributed to your hand trouble Ron?
I mean , I definitely haven't taken it easy on my hands , most of my fingers are crooked from being broken, smashed, and so many burns/electrical incidents, they can't be calculated!
Working in a cabinet shop sanding 8 hours a day did make them like catchers mitts for awhile but that was temporary.
So I'm wondering if I should start doing things differently (now that I've outlived my own life expectancy, Haha)?
 
I have a 10-10S on the bench. 140psi compression, has spark, will not pop. Filthy saw. It has had a hard life. I am going into it. Starting with coil and lamination gap. Any guesses? Lets make a game out of it so to speak. I will ship the FIRST correct diagnose a new style electronic 10 series coil. So let's play a game. Each person gets one question that I will answer as I go.

Issues so far:

Has spark will not pop.
Leaks fuel at gas line pass through tank.
Tank half seal leaks.
Though compression tested good, turns easy by hand.
after squirting fuel in plug hole can easily turn saw by hand via flywheel with plug in Decomp out.

Copy this in reply with questions and guesses.
Lets have fun and Good Luck!
I had the 10-10S running this morning. It was not the woodruff key or a timing issue. My first trouble shooting step found part of the issue. The saw would run but not good.

I have torn it all the way down. So there are two issues.

Issue one caused saw not to run even with spark.

The second issue concerns the problem with saw not running correctly.

Ask you question if you wish and take you guesses Gentlemen. I will tell you the second issue is a rarer one to encounter (at least for me).
 
What do think contributed to your hand trouble Ron?
I mean , I definitely haven't taken it easy on my hands , most of my fingers are crooked from being broken, smashed, and so many burns/electrical incidents, they can't be calculated!
Working in a cabinet shop sanding 8 hours a day did make them like catchers mitts for awhile but that was temporary.
So I'm wondering if I should start doing things differently (now that I've outlived my own life expectancy, Haha)?
May just be me - I have always enjoyed running OPE. The handle vibrations from old push mowers and a walk behind Gravely would practically put my hands to sleep as a kid. The only street bike I ever owned was a Yamaha 650. Once you hit 45 mph it would vibrate like crazy. I took it on the Interstate only once - within 45 miles I was becoming numb from the hips down and I was about to lose my grip, so I turned back. It was a long ride home. Years later, my left hand would go numb using the 700. Not long thereafter I brought an old Gravely, I couldn't run it for 30 minutes straight. I discovered a/v saws and didn't look back. I also read dozens of posts on AS discussing potential long-term damage due to repetitive exposure to vibrations, that coupled with not finding any rugged anti-vibe gloves, let me to leave the 700 on the shelf. Only after running Bruan's 1010s on occasion, did I return it to work.

Here is one of the threads that got my attention: www.arboristsite.com/threads/any-of-you-have-issues-with-your-hands

Ron
 

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