McCulloch Chain Saws

[kmcinms]

Pro Mac 10-10

Ahh, popped off the Pro Mac 10-10 tonight, sort of. This saw wants to come out and play! The tank is in cruddy shape, as is the fuel line. Not knowing the shape of the saw I checked the cylinder through the plug hole. Very clean, with a bit of old mix wiping up and down the walls, so I poured some fresh mix in through the head and spun it over a few times and lightly flushed it out.
I dribbled a bit of mix down the carb and popped that puppy off. It sounds strong.
This saw has great compression and the cylinder looks pristine. I pulled the carb and it has had some moisture sitting in it. Might need some carb parts to complete this one. What do I need to do on the fuel line? Can you still get this piece?
Also, there is no muffler to speak of after the initial sheet metal flange mounted to the jug.
Can someone tell me which carb kit to buy and what carb this is? Any other things to look at while I'm replacing parts. Preciate it.

 

[boda65]

I believe they all had Walbro SDC carbs on them. The kit number is K10-SDC. I have had better luck with the genuine Walbro kits than I do with the aftermarket ones.
A bad time to ask about the fuel line. I am still steaming from putting one on a pro mac 700 this morning. Fit too loose through the hole and leaked like a sieve. Few things irk me more than something brand new that doesn't work as it should. Anyways, I wrapped it multiple times with teflon tape, then pulled it through again. It's holding for now, but who knows long term.
They are readily available on the well known auction site. Stens makes them still. I don't know if one source is any better than another, I would spend a little more if I knew one would fit correctly.
Jim

 

[HeRoze]

You mean the nut that goes in the center of that photo, right? That's on the crankshaft. My reccomendation is to set the piston above the exhaust port then cram a peice of rope through the plug hole to serve as a piston stop. ===.

Been there, done that. It is properly prepped for removal, and I don't like powered impact wrenches on old crappy metal. Check that I mentioned that the flywheel isn't moving. I do have the cylindar crammed full of nylon rope, but the piston isn't trying to move, either.

Yes, I mean the nut on the end of the center shaft in the clutch assm. When I turn it, it just spins in place. I'm afraid I may have a parts saw. I was kinda' hoping there was something weird about the 640 where this wasn't the case.

 

[kmcinms]

I believe they all had Walbro SDC carbs on them. The kit number is K10-SDC. I have had better luck with the genuine Walbro kits than I do with the aftermarket ones.
A bad time to ask about the fuel line. I am still steaming from putting one on a pro mac 700 this morning. Fit too loose through the hole and leaked like a sieve. Few things irk me more than something brand new that doesn't work as it should. Anyways, I wrapped it multiple times with teflon tape, then pulled it through again. It's holding for now, but who knows long term.
They are readily available on the well known auction site. Stens makes them still. I don't know if one source is any better than another, I would spend a little more if I knew one would fit correctly.
Jim

10-4. Preciate that.

 

[cpr]

Been there, done that. It is properly prepped for removal, and I don't like powered impact wrenches on old crappy metal. Check that I mentioned that the flywheel isn't moving. I do have the cylindar crammed full of nylon rope, but the piston isn't trying to move, either.

Yes, I mean the nut on the end of the center shaft in the clutch assm. When I turn it, it just spins in place. I'm afraid I may have a parts saw. I was kinda' hoping there was something weird about the 640 where this wasn't the case.

Ooh, that doesn't sound good. I hope for your sake it's something we're both missing here. Sorry, out of ideas at this point.

 

[djones]

only thing left for you to do now is to split the nut with a chisel and hammer and then remove everything else and look inside.

 

[HeRoze]

only thing left for you to do now is to split the nut with a chisel and hammer and then remove everything else and look inside.

I was really hoping for news of a sheer pin and coupling, but...!

Upon further investigation....

I got a pair of channel locks fully expecting to yank the nut and a chunch of shaft out of the saw.

Instead, it appears what has happened is that someone, sometime, stripped the threads on the shaft, but not so much that I didn't feel resistance with my 1/2" ratchet handle (in other words, it felt like something was resisting even with a heavy wrench).

In a possible effort to make up for the fubared threads, the shaft is peened mushroomed slightly holding the nut on. Or maybe someone dropped the saw square on the shaft peening the end and the threads were stripped at a later time.

Sooo, splitting the nut may be in order. I pulled the gear cover so I have room.

Old stuff is bizarre, and this is no exception. The insides, chain, bar, sprocket and other things that would indicate use are almost like new. what little I can see of the cylinder looks fine. everything on the outside of the saw looks like crap. for some reason the bearings on the gearbox are marginal, at best. I suspect this saw was transported and stored poorly, but used very little.

At least it isn't as trashed as I thought it was last night.

 

[cpr]

It'd be nice if a thread chaser could clean it up, but I fear you may be shopping for a crank.

 

[promac850]

It'd be nice if a thread chaser could clean it up, but I fear you may be shopping for a crank.

What if someone welded over the old threads and rethreaded it by cutting threads into the welded portion? Figure it would work, might be quite cheap too.

 

[HeRoze]

What if someone welded over the old threads and rethreaded it by cutting threads into the welded portion? Figure it would work, might be quite cheap too.

maybe. or drop to the next smaller size with a die set. i'm still thinking this one through. i'll chase the threads first, but I doubt it will hold.

this particular nut doesn't really take any axial force... thinkin'....

 

[leeha]

maybe. or drop to the next smaller size with a die set. i'm still thinking this one through. i'll chase the threads first, but I doubt it will hold.

this particular nut doesn't really take any axial force... thinkin'....

The crank should be the same as a direct drive saw.
Which would make it a lot easier to find and cheap.
Thats the way i would go.


Lee

 

[promac850]

Not much axial force, but it does have to hold that clutch on, which it must be strong enough to resist stripping the threads on it's own by the centrifugal forces of the crankshaft and clutch. As the nut wants to tighen when the saw is running, if the threads strip, then the clutch will follow the nut into the clutch cover, eve if the saw was only tilted a tiny bit to the right.

 

[cpr]

Get a new crank. A few years back I started a project saw with no bar, chain, or cover. I wound it up then backed off and looked just in time to see the clutch float back and forth. I immediately ducked, heard it hit the floor a second later followed by a bang on the open garage door above my head. The dog found it 2 days later in a flower bead outside and around the corner... Lesson learned, don't risk it.

 

[promac850]

Get a new crank. A few years back I started a project saw with no bar, chain, or cover. I wound it up then backed off and looked just in time to see the clutch float back and forth. I immediately ducked, heard it hit the floor a second later followed by a bang on the open garage door above my head. The dog found it 2 days later in a flower bead outside and around the corner... Lesson learned, don't risk it.

Wow, scary.

Had a similar incident with flying objects, but it was a connecting rod cap from a Toro S200. It was running full out (only way they run, lol) and I heard it scream louder and louder and louder, then clunk, BANG!

Threw the cap right through the engine block and it hit the side of the pole barn so hard it disintegrated. Damn, that was fun. :bulgy-eyes: Thirty bucks down the drain thanks to the key switch not working. Was about to pull the plug wire off the spark plug when it blew up.

 

[cpr]

It most certainly got my attention, on the other hand, that's the best thing that English Setter's ever been on point over!!! Hell yeah he got treats! Love that dog!

 

[HeRoze]

Get a new crank. A few years back I started a project saw with no bar, chain, or cover. I wound it up then backed off and looked just in time to see the clutch float back and forth.====

Heh - been there, done that too I was test-running my little 2300CVA and saw that weird floating clutch thing. I was outside near both cars and held the thing away from my head and parallel to the cars. It flew apart when it hit the ground. I did finally find all the pieces. my dogs weren't any help at all, though.

that was because I thought I could fire it briefly without the cover. i knew better, but lazy overcomes sense too often.

i probably could downsize the shaft and rethread, but... i'll take a cheap replacement crank over a rig job anytime though.

 

[cpr]

Here's a super post!

The Super 44 and Super 250 ready for tuning and public annoyance. I expect my name broadcast as a public offender over the 1380 WPHM towers winking in the background "I'm Bill Gilmer, on the Blue Water News Network, last night a local man..." he he he.

<iframe title="YouTube video player" width="640" height="390" src="http://www.youtube.com/embed/BA_E5xo_UmA" frameborder="0" allowfullscreen></iframe>

 

[leeha]

Music to my ears Chris,
They sound great.




Lee

 

[Brian13]

Gotta love that sound for sure!!!! Looking forward to seeing videos of those two in wood.:msp_thumbsup:

 

[heimannm]

Music, sweet, sweet music...

Mark