Mcculloch Super Pro 125c Complete rebuild.

[watsonr]

The lapping compound is for a flywheel that doesn't quite fit the shaft and is a little rough around the inside of the taper. If you have a good flywheel and the mating surface is smooth, there's really no need to do that.

 

[hkusp9]

 

[cbfarmall]

Same for me with the DD Macs with tapered cranks that I've worked on Chris. I just wish I could use the same trick on a Homelite 750 that I'm working on now. For those that don't know (and Chris most assuredly isn't in that group) that particular Homelite clutch is threaded onto the crank. That clutch has most likely been on the saw since new (judging by the condition of the clutch bearing), and is being a real ******* at the moment...

I got this one. For that clutch, and most other threaded clutches (3 and 6 shoe), I use the 3 prong clutch Stihl tool that is intended for the 075. Only modification I made, is I slightly tapered the prongs to slide them between the shoes easier. It's strong enough to use a cheater pipe on.

Chris B.

 

[Eccentric]

I got this one. For that clutch, and most other threaded clutches (3 and 6 shoe), I use the 3 prong clutch Stihl tool that is intended for the 075. Only modification I made, is I slightly tapered the prongs to slide them between the shoes easier. It's strong enough to use a cheater pipe on.

Chris B.

That's pretty slick Chris. I made a homebrew spanner to slip into the two holes in the clutch spider.................and busted my spanner wrench (without breaking the clutch loose). Cut my hand in the process too. I'll look into the Stihl 075 clutch tool. The saw I'm working on has a 6 shoe clutch.

 

[Jon1212]

I have had multiple people message me through this site to tell me that they're tired of ypur crap and the negative attitude of you and alot of guys like you on this site. Alot of people have turned away from this site because of you. My thread, stupid and goofy or not, is a sticky because it draws in members and readers. I may be controversial, but i know how to draw a crowd at dinner parties and on internet chat forums where membership numbers and the number of readers dictate what kind of advertising fees the site can demand from its sponsors.

Again, please Thomas1,leave me the hell alone.

Charles you forgot the 82cc Sp-80 thru DE-80 Macs...



Tom is the guy who made this thread a stickie...

I suppose I deserve some of the Blame/ Credit for this as well, since I gave Tom a thousand credits to purchase the "stickie" option.

 

[thomas1]

I suppose I deserve some of the Blame/ Credit for this as well, since I gave Tom a thousand credits to purchase the "stickie" option.

Thanks, buddy. :msp_thumbsup:

In the interest of learning, Hkusp9 how did you split the cases and why was jb weld needed?

 

[cpr]

Still curious, as well, how you got it apart. I've sucessfully patched a cracked one by squirting some 1194 in through the cap, flowing it back and forth over the cracks over a period of minutes, then letting it sit level over the patch area for a couple of days.

 

[rwoods]

Thanks for the kind words Sir.

So far the only thing that ive perceptibly messed up was the flywheel, which already had one foot in the grave. And like you said, i learned about valve lapping compound and will be ready to rock when my new flywheel comes in.

Everything else has gone mostly smoothly. Im painting tonight and i wasnt paying close enough attention and painted the engine shroud yellow when i wanted to paint it black, but Ive seen a million of these things online that are painted a million different ways, so i guess its whatever floats your boat on that.

Finally, im pretty sure that im not going to put the oil seals and new rings and check the bearings and press the crankcase cover back on myself yet. Im learning alot, but im not completely comfortable tackling that on my first super pro rebuild.

On an interesting note. I found a great deal on another 125sp last week and its supposed to be delivered tomorrow so im pretty excited about that.

Oh, also... I need to find the lower handle antivibration mount thingies.

I think the technical terms are grommet-84661 and washer-grommet-110675 and most importantly, lower mount-83818. Ive seen a couple of small online lawnmower type of repair shops that show to have them, but I'll bet my lunch that they arent in stock.

These saws must have some sort of homing device built into them. Search forever to find one, you get it then they just start calling your name. Just remember that unless you win the lottery (or have a fortune of your own), you can't save them all. Ron

 

[hkusp9]

These saws must have some sort of homing device built into them. Search forever to find one, you get it then they just start calling your name. Just remember that unless you win the lottery (or have a fortune of your own), you can't save them all. Ron

You're telling me. honestly, im in way over my head on the first one already and im still sinking money on it like its going out of style. If you remember, i was searching for one for a few weeks and located it on craigslist out of Oregon on craigslist in a lot of 14 other saws and the guy was asking $500 for all of them and was unwilling to break up the lot. I ended up having to buy all of the saws together, and arrange for shipping to get just this one. Most of the other saws are in various states of serious disrepair and some of them look so bad that i dont even want to try to mess with them.

To make matters worse, i went from a 125c that i could have probably replaced a crank seal on and run, to one that im completely rebuilding and replacing EVERY consumable item on. The cost of that is adding up VERY quick. Also, I still have to pay to ship out the engine to a kind member who offered to replace the rings and seals and then pay for the work (not complainant about that part, just saying).

So basically when its all over and done with, this $500 SP 125c is going to be a $1,000 SP 125c and half of my garage is now full with the rotting carcasses of 13 other poor beleaguered Mac saws that i cant save on my own and cant step over to get around either. ps:

This one that coming today, im going to put some gas it in it and run the darned thing. If it doesnt explode or sound like its going to explode, its going to most likely stay the way it is... for a while....

of course i say that and then i look at that 200psi comp photo of the one with the squish band cut and think to myself, hey, it would be too hard to have it bored and ported......:bang:


EDIT: oh good lord help me, theres another one in the classifieds on here right now for 600 that looks to be in perfect running shape and still has the muffler cover intact. Somebody please go buy that thing out from under me. I dont even own any trees and i already have 2 of these beauties to contend with!

 

[ozflea]

Now he goes and tells me this is dangerous after i tried this method last night so i could see the full effects of exploding gas man i look like Al Johnson ............... thanks ol bubby

McBob.................. neally ex McBob of and i wont be needing a hair cut for quite a while

 

[cpr]

10-4. I might have tried pumping it full of grease. My luck, I'd have blown the crack out of it and having to find new.

 

[hkusp9]

10-4. I might have tried pumping it full of grease. My luck, I'd have blown the crack out of it and having to find new.

Grease might work too, but it would be a whole hell of a lot of grease that you would have to pump in there and it would make an unholy mess that would probably be impossible to clean up. Plus you would still have to pressurize the grease like i did with the air compressor so the danger is still just as present. Also, mine was leaking at the two seams only, where the tank halves come together.

If you have a crack thats not on the seams, and you try this method, you will probably blow out the side of your tank. I would not recommend trying this method if you have any problem other than leaking gas at the glued together seam.

Finally, the reason i used water instead of grease or whatever other medium is that ive seen explosive breaching guys use water charges with C4 to make very precise controlled breaches on doors and walls and stuff.

Apparently water will actually controll and direct the force of an explosive in a specific place and is great for actually cutting a hole in the center of a door or wall instead of just blowing the whole thing to bits. I figured if water works for that it would work for this.

 

[cpr]

Seam leak? That's the problem my stocker had. 1194 worked as above. No explosions, though.

 

[hkusp9]

Seam leak? That's the problem my stocker had. 1194 worked as above. No explosions, though.

That just means that you werent trying hard enough! :msp_biggrin:

I figure that the benefit of splitting and JB welding the tank is that i wont have anymore tank leaks again... Ever.

 

[Jon1212]

opcorn: I truly hope that there aren't any newbies reading this thread that take any single thing you say seriously.

C'mon Bob, he put the legally bullet proof Disclaimer in his post before revealing that he was a hairline crack away from winning a Darwin Award.

 

[ozflea]

C'mon Bob, he put the legally bullet proof Disclaimer in his post before revealing that he was a hairline crack away from winning a Darwin Award.

Yeah but that was way after the fact i can see a law suit coming ................... loose lips sink ships .... and i like this bit ....... Good luck, and remember if you blow yourself up dont come crying to me.

 

[Gologit]

Okay...you guys that work on Macs and know them well...was that post truly a dangerous bit of advice?
I'm no saw mechanic and a lot of the guys on here aren't. Would following his advice have the potential to harm a person trying the same thing?

 

[cpr]

Well Bob, I gotta go with yes. That's why I gave up trying to conceive how to split them and went the 1194 + patience method on the 2 I patched. Both have held nicely for 6 months, including the 101 monster that shakes and bakes.

 

[russhd1997]

Okay...you guys that work on Macs and know them well...was that post truly a dangerous bit of advice?
I'm no saw mechanic and a lot of the guys on here aren't. Would following his advice have the potential to harm a person trying the same thing?

:hmm3grin2orange::hmm3grin2orange::hmm3grin2orange:

 

[Jon1212]

Okay...you guys that work on Macs and know them well...was that post truly a dangerous bit of advice?
I'm no saw mechanic and a lot of the guys on here aren't. Would following his advice have the potential to harm a person trying the same thing?

I don't think someone has to be a saw mechanic to know that introducing high pressure air into a sealed container of unknown structural integrity, that was designed to contain liquid at atmospheric pressures is a really bad idea that could have catastrophic results.
But then again I try to approach things with logic, and reason.

Yeah, I know. This post will get reported for being "negative"........blah.....blah.....blah.....