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Mcculloch Super Pro 125c Complete rebuild.

hkusp9

hkusp9

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Ok, so this is the super pro that i received last week. I will be posting photos as i take this thing down and put it back together and go along.

Anyhow, right now im messing with it and its missing super bad. Im pretty sure that the needs a carb rebuild since its been sitting for so long, but im wondering if that could be making it miss or if its an ignition issue maybe.


<embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player.swf" flashvars="file=http%3A%2F%2Fvid952.photobucket.com%2Falbums%2Fae4%2Fhkusp999%2FB7E607FA-6219-4C49-8237-18469738F81A-5279-000009C59352B542.mp4">

Im going to go through the carb here in a second and take a look at it.

Also, that puddle in front of it is a massive pile of oil. The oiler definately works! I also like that its gushing oil, since i want to make sure that the chain and bar are taken care of and the saws happy. Oil is cheap and I will happily feed this big beautiful beast!
 
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leeha

leeha

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Replace the points and condenser.
They're readily available.
That saw sat for a long time. No
dought they're messed up.



Lee
 
hkusp9

hkusp9

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Replace the points and condenser.
They're readily available.
That saw sat for a long time. No
dought they're messed up.



Lee

its a tillotson HS124B carb. the Gaskets look to be pretty dried and stiff.

Im goign to mess with the points and condenser now and see if i cant clean them up a little with my sandblaster or something.
 

CM76

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its a tillotson HS124B carb. the Gaskets look to be pretty dried and stiff.

Im goign to mess with the points and condenser now and see if i cant clean them up a little with my sandblaster or something.

I couldn't help myself here - Do not go anywhere near the points or ignition system components with a sandblaster!!!!!

Heed Lee's advice and replace the condenser and points with new items. They are cheap and easily found. The points can be dressed, but a faulty condenser requires replacement.

Best of luck with the rebuild - they are a great old saw to work on and run.

Chris.
 
hkusp9

hkusp9

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I couldn't help myself here - Do not go anywhere near the points or ignition system components with a sandblaster!!!!!

Heed Lee's advice and replace the condenser and points with new items. They are cheap and easily found. The points can be dressed, but a faulty condenser requires replacement.

Best of luck with the rebuild - they are a great old saw to work on and run.

Chris.


well, honestly ive never cleaned points. so ill take a look at them and see how best to fix them up. The condenser is obviously a complete replacement item assuming i dont put a chip in it and toss both. Im about to block the piston from the exhaust port with some climbing rope and take the flywheel off so i can look at the points.

Im definately learning here so help me, does the flywheel nut come off clockwise or counterclockwise?


Nevermind, the nut was barely even on there handtight.
 
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CM76

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well, honestly ive never cleaned points. so ill take a look at them and see how best to fix them up. The condenser is obviously a complete replacement item assuming i dont put a chip in it and toss both. Im about to block the piston from the exhaust port with some climbing rope and take the flywheel off so i can look at the points.

Im definately learning here so help me, does the flywheel nut come off clockwise or counterclockwise?

The flywheel nut has a R/H thread, whereas the clutch is L/H. R/H = counterclockwise for removal.

Chris.
 
hkusp9

hkusp9

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Annnd i think im done now. That was fast.

I dont have a specialized flywheel puller for this thing and unlike other saws. Im not about to beat on the crankshaft with a hammer....

Im seeing about a million universal flywheel pullers online that should, but none that are sold by local stores. Anybody bought one that screws into the two holes on the flywheel a brick and mortar joint?
 
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Tzed250

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You don't need to "beat" on the crankshaft. Turn the nut over and thread it back onto the crank enough that the end of the crank is just below the nut. Hold the saw up off of the bench by the flywheel in your left hand. Strike the nut with a brass hammer or hard mallet and the FW should pop loose. Works great on my SP125.
 
hkusp9

hkusp9

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You don't need to "beat" on the crankshaft. Turn the nut over and thread it back onto the crank enough that the end of the crank is just below the nut. Hold the saw up off of the bench by the flywheel in your left hand. Strike the nut with a brass hammer or hard mallet and the FW should pop loose. Works great on my SP125.

Yeah, i did exactly that. I have it 5 or 6 light raps with the hammer and 3 or 4 good stiff ones before i lost my nerve and quit. I dont want to mess up the threads on the crankshaft and as of now everything is as it was when i started. Im really excited about this saw and dont want to tear into it like a blind idiot as i have done with some previous blunders which i publicized on here.

Im going to go buy one of those universal flywheel pullers tomorrow from somewhere, anywhere, and take this thing apart the right way, where i can have some confidence in my work.

Also, I had a guy tell me that ALL mcculloch condensers are the same across model lines. Does this mean that i can take a condenser off of a mini mac 25 or 35 and put it on my SP125????

Surely that wouldnt work right?
 
Bill G

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Yeah, i did exactly that. I have it 5 or 6 light raps with the hammer and 3 or 4 good stiff ones before i lost my nerve and quit. I dont want to mess up the threads on the crankshaft and as of now everything is as it was when i started. ................

You will not mess up the threads if you do it RIGHT. If you are very worried then get two thin nuts and tighten them together at the end of the crank with no threads exposed. Then slip a socket over them and give it ONE HARD WRAP WITH A REAL HAMMER. You will have the flywheel off with no damage
 

CM76

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Yeah, i did exactly that. I have it 5 or 6 light raps with the hammer and 3 or 4 good stiff ones before i lost my nerve and quit. I dont want to mess up the threads on the crankshaft and as of now everything is as it was when i started. Im really excited about this saw and dont want to tear into it like a blind idiot as i have done with some previous blunders which i publicized on here.

Im going to go buy one of those universal flywheel pullers tomorrow from somewhere, anywhere, and take this thing apart the right way, where i can have some confidence in my work.

Also, I had a guy tell me that ALL mcculloch condensers are the same across model lines. Does this mean that i can take a condenser off of a mini mac 25 or 35 and put it on my SP125????

Surely that wouldnt work right?

You are on the right path. Don't try and get the engine apart without the proper gear

Chris.
 
Ambull

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A 3-finger gear puller works really good on the flywheel. BTW if you have a spark problem, you should check / change the plug first.
 
belgian

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Replace the points and condenser.
They're readily available.
That saw sat for a long time. No
dought they're messed up.


Lee

Although this is for sure the best method, this solution might be a bit drastic at first.
Looks like the OP's saws is missing a few fires, so cleaning and correct gap setting of the points would be my go to solution first. I am almost convinced that will do it.
If the condensor were messed up, it would not fire at all.

PS. to OP : also clean carb area of foreign objects that might get sucked in when you test saws without air filter ... I noticed some debrie dancing in the carb box waiting for a chance to hop in...
 
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bob15

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Personally, i would scrap the points and ignition and buy a Nova II ignition module. I cannot stand points, whether its in a car or a saw.

A harmonic balancer puller or a bar-type puller would work best for pulling flywheels.

Don't remember the bolt spread on the saw, but something like this would work if the bolts aren't beyond 4.5" apart:

CJ83C, Puller, Pully and Gear

If further apart, this will work:

CJ85-1, Yoke, 3"-6 1/2"

Then you must buy the pressure screw and tip. I like the Snap On because the pressure screw tip is replaceable.

OTC also sells bar pullers. Look for # 927, 7393 or 522 on amazon, ebay or I believe McMaster-Carr

Back to the saw, is there any crankshaft movement left to right? I had an 125 run similar and found the bearing was going and needed replacement, along with the adjoining seal. Replaced the bearing seal, added electronic ignition, and I was running again. On you saw it also would hurt to rebuild the carb, replace the fuel filer and be sure the pulse line isn't loose.


bob
 
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