Mastermind
Work Saw Specialist
Yeah......but you're a Tennessean.
Great post. :msp_thumbup:
Mcculloch Super Pro 125c Complete rebuild.
- Thread starter hkusp9
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Yeah......but you're a Tennessean.
Great post. :msp_thumbup:
Well said.
Jon1212
Riff Raff Fart Knocker from other Forum's.
Perhaps one of the most well written, concise posts I've read on AS in quite awhile.
Repped for your straight talkin' ways, and stuff.
If it's a bear to pull over then there's no need to check compression.
Unless you just want the number. That flywheel should be ok.
If the saw were mine, I would replace both crank seals, oil tank
and stuffer gaskets, Reed plate gasket, And check the intake boot.
Crank bearings never go in these old Mac's. At least all the ones
i have had appart were still good. They are a very well made motor
and were meant to run for hours day in and day out.
Lee
Unless you just want the number. That flywheel should be ok.
If the saw were mine, I would replace both crank seals, oil tank
and stuffer gaskets, Reed plate gasket, And check the intake boot.
Crank bearings never go in these old Mac's. At least all the ones
i have had appart were still good. They are a very well made motor
and were meant to run for hours day in and day out.
Lee
bob15
ArboristSite Operative
allright. So heres the progress.... Good and bad
I went and bought this generic auto parts store puller tool and got some bolts and washers from home depot that would fit it. Worked like a charm at budging the flywheel free, but it took some more work to get the flywheel to actually come free of the key which was a little chewed up.
Just started reading you post again and want to mention in the future about keeping the nut on the crankshaft when using the puller. Just loose enough to allow for the flywheel to pop off the crank. Reason being sometimes the puller can bugger the end threads or put an ever so slight peen on the threads. The nut will prevent that and/or can also act as thread chaser when removing it off the crank.
bob
Not to mention that the nut will also keeping the flywheel from bouncing across the room once it does let go. Ron
bob15
ArboristSite Operative
It sounds like you also speak with experience of having items pop off at the one moment you're not ready to catch them. I never had that issue before :msp_wink:
bob
thomas1
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hkusp9
ArboristSite Operative
I was prying on the flywheel not out of rage or anything, but because that one was pretty well already garbage anyway and all i needed is the starter pawls off of it. I actually know a local place to get the studs from so i wasnt worried about losing those either.
Also, on the 125c flywheel, the holes for the stud didnt go all the way through the flywheel so i couldnt tap them out from the back.
Finer points aside, the flywheel i assembled and put on it now turned out perfect though.
Ill take some pics when i tear it down more tonight.
hkusp9
ArboristSite Operative
Ok, so really tore into it after work tonight. Got home late (long story) and didnt get on it till 10:30 pm but once i did i didnt stop until about 3am.
I have the tank sandblasted too now and got everything apart on it and located the source of the gas leak, and no you wont guess in a million years what the previous sick f^%K of an owner did to this poor thing in that regards.
Got the oil tank pulled off the front but cant get the bottom crankcase cover off the cylinder. The gasket is on there really good. Need to find a new one of those anyway... Also I wasnt able to get the metal cover plate that cover the reeds off at all. All the bolts are off if it, but that sucker is stuck on TIGHT still from old gaskets.
Also, i cant get the clutch off. I've read most of my manuals and it seems like the thing should just pop off but i cannot get the darn thing off. I pulled on it by hand, and then lightly tapped on the crank while holding it by the clutch and it wont come off. Im not going to screw with it anymore without more guidance from yall, but It needs to come off so i can check the crankshaft seal and replace the very well worn sprocket thats underneath it....
I really want to tear this thing down enough to have a professional check the cylinder and rings and oil seals and then replace all the gaskets before i put it back together. Ive come this far and put this much effort into it.... The thing is going to cost me the same in repairs as what i have in it, so i figure that i should do it right and get the thing perfect when its done.
I will post some detailed photos tomorrow. Photos that will blow you away.
Also, i came up with a really innovative and effective way to disassemble something that I bet may of you have never even though of. Im going to bed now, but I'll add more tomorrow.
I have the tank sandblasted too now and got everything apart on it and located the source of the gas leak, and no you wont guess in a million years what the previous sick f^%K of an owner did to this poor thing in that regards.
Got the oil tank pulled off the front but cant get the bottom crankcase cover off the cylinder. The gasket is on there really good. Need to find a new one of those anyway... Also I wasnt able to get the metal cover plate that cover the reeds off at all. All the bolts are off if it, but that sucker is stuck on TIGHT still from old gaskets.
Also, i cant get the clutch off. I've read most of my manuals and it seems like the thing should just pop off but i cannot get the darn thing off. I pulled on it by hand, and then lightly tapped on the crank while holding it by the clutch and it wont come off. Im not going to screw with it anymore without more guidance from yall, but It needs to come off so i can check the crankshaft seal and replace the very well worn sprocket thats underneath it....
I really want to tear this thing down enough to have a professional check the cylinder and rings and oil seals and then replace all the gaskets before i put it back together. Ive come this far and put this much effort into it.... The thing is going to cost me the same in repairs as what i have in it, so i figure that i should do it right and get the thing perfect when its done.
I will post some detailed photos tomorrow. Photos that will blow you away.
Also, i came up with a really innovative and effective way to disassemble something that I bet may of you have never even though of. Im going to bed now, but I'll add more tomorrow.
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LOL I have done that before. I think it was a harmonic balancer on a 350 Chevy. Got the puller as tight as possible without breaking, and then gave the balancer a tap with a hammer. And watch her fly.....
The clutch nut is a LH thread, and you should be able to get that off. The rest of the clutch is press fit on a tapered shaft, and often needs a gear puller. I use a 3 finger one, and hook the fingers around the clutch. The crank has a center hole to hold the puller straight. It always comes off. At this point just be thankful you are not working on a Homelite 2100. Now those clutches are tough to get off.
You will need a puller for the clutch.
It's on a tapered shaft like the flywheel.
It may or may not be keyed.
Lee
It's on a tapered shaft like the flywheel.
It may or may not be keyed.
Lee
If the crank shaft has a key you don't want to pull on the clutch drum. With the nut off you can tell if there is a key or not, in fact if memory serves (not always reliable) the keyed crank shaft has a standard RH thread and the non-keyed crank shaft has a LH thread.
Many clutches have a couple of holes you can take advantage of and use a puller.
An 088 boot can be made to work, but the passage is not as large as the original McCulloch.
Mark
Many clutches have a couple of holes you can take advantage of and use a puller.
An 088 boot can be made to work, but the passage is not as large as the original McCulloch.
Mark
cpr
Addicted to ArboristSite
Glad you're excited to have it, but you do need to slow down. The 125"c" means chrome bore. Translation: NO do overs. If you wreck that bore, you're pretty much done and need a new block.
I still don't see a compression test. That is step 2 after pulling the muffler for a look-see. My stock 125c makes 185psi, my ported kart saw (no decomp) makes 195, and my Homie 2000 over 210. Yes, I rode all around the floor getting it done, but inertia is your friend.
I wouldn't monkey with the points timing, there's nothing but a headache there. Get feeler gauges, set it at .019 once, run it, check it, reset to .019 (I don't care who you are, they all move after the first run) and enjoy it.
Bob is correct on the 125c's having 5 deg. flywheels, at least mine does, but it is unmarked (the kart ones I have seen have a 5 stamped on one of the pawl travel-limit studs). Below is a picture of the difference. 0 on left, 5 on right. If you google McCulloch 5 degree flywheel, you'll turn up kart parts places that have them. My 125c, ported 101, and MC-91 have them, the rest don't. The 797s will hang with the 5er 125 no problem and still rip you hand off starting it.
Check that boot, it is, more than likely, the source of your air-leak, after that, check the oiler tank. If you had it off, it can work the bolts loose and suck through the impulse passage for the pump.
Go easy on it after reassembly. These Macs are notorious for shedding fasteners after reassembly. After the 2nd go round, most of that will stop. Torque wrenches are your friend, but still verify.
EDIT: SIDEBAR, Lee I already boxed the CP125 motor to send out tomorrow. I don't want to open it, but I'm curious which flywheel is on that one...
I still don't see a compression test. That is step 2 after pulling the muffler for a look-see. My stock 125c makes 185psi, my ported kart saw (no decomp) makes 195, and my Homie 2000 over 210. Yes, I rode all around the floor getting it done, but inertia is your friend.
I wouldn't monkey with the points timing, there's nothing but a headache there. Get feeler gauges, set it at .019 once, run it, check it, reset to .019 (I don't care who you are, they all move after the first run) and enjoy it.
Bob is correct on the 125c's having 5 deg. flywheels, at least mine does, but it is unmarked (the kart ones I have seen have a 5 stamped on one of the pawl travel-limit studs). Below is a picture of the difference. 0 on left, 5 on right. If you google McCulloch 5 degree flywheel, you'll turn up kart parts places that have them. My 125c, ported 101, and MC-91 have them, the rest don't. The 797s will hang with the 5er 125 no problem and still rip you hand off starting it.
Check that boot, it is, more than likely, the source of your air-leak, after that, check the oiler tank. If you had it off, it can work the bolts loose and suck through the impulse passage for the pump.
Go easy on it after reassembly. These Macs are notorious for shedding fasteners after reassembly. After the 2nd go round, most of that will stop. Torque wrenches are your friend, but still verify.
EDIT: SIDEBAR, Lee I already boxed the CP125 motor to send out tomorrow. I don't want to open it, but I'm curious which flywheel is on that one...
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RandyMac
Stiff Member
A stock 797 will steal the dessert out of a 125Cs lunch and maybe the sandwich too.
cpr
Addicted to ArboristSite
SSSHHHHH! My price inflation days are over :hmm3grin2orange:.
thomas1
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What happened?
Jon1212
Riff Raff Fart Knocker from other Forum's.
Tom,
Is there a special tool that can be used for removing small bits of magnesium from human eyeballs? Just curious.........
thomas1
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Tom,
Is there a special tool that can be used for removing small bits of magnesium from human eyeballs? Just curious.........
Being that magnesium is not magnetic, in the traditional sense, I have been trying to find a solution to that problem.
I've read that if you pass a sufficient electrical current, like 60 amps at 220v, through a piece of tungsten carbide that it will become fairly attractive to small amounts of magnesium.
I have a piece of material coming and will let you know how it turns out. Until that gets here, you will have to keep using your vise-grips.
