McCulloch Chain Saws

[heimannm]

Next up is this 1-75...I have a 1-85 that runs exceptionally well and I really want to see what the direct drive counterpart can do.









It has a few problems, not the least of which is low compression.

Mark

 

[heimannm]

I didn't measure the ring end gap, but I'm not sure I had enough feeler gauges to add up to the gaping hole anyway.



Second ring on top of the first.



The rings were also a bit stuck in the piston from setting. I think everything will clean up nicely and I just happen to have a set of rings on hand.





The oil tank was cracked , probably from someone trying to lever the saw out with the bar stuck. Since I don't plan on more that a little cookie cutting I will try to patch the tank with some JB Weld and go easy on it. If it doesn't hold up, I guess I'll have to locate another tank.

Mark

 

[Jethro 2t sniffer]

You had the only keyed crankshaft without a chipped keyway left in the entire world and....

If you could drill and tap the crankshaft and make a "cap" to hold the clutch, that would be my first choice but I don't have the ability to weld it up and then try and recut the threads...that material is very hard by the way.

The 250 crankshaft won't work for the Super 250, the 250 is an 80cc saw with 1.375" stroke and the Super is 87 cc with 1.5" stroke. Besides that, the Super is 9/16" at the clutch with the tapered end and the 250 is 5/8" at the clutch and threaded for the clutch.

Ed - According to the IPL's the Super 44 and 1-75 use the same clutch. More on the 1-75's to follow...

This helps illustrate how the spring clip gets wedged in there. Be sure to work both sides as you're pushing it back and get it all the way to the back of the oil tank.

View attachment 1087161

Mark

I'm sorry Mark

How hard is very hard?

Im thinking drilling n taping an M5 thread and machine said thread on the end of a 10mm threaded rod with a good bevel and then fiz around it. I can use the saw as a "chuck" of sorts to get the centre of the crank and hopefully it might hold

 

[matt_lamb_160]

Well I was happy to and was fully prepared but then it had amazing spark soo.... wahoo

The big old McCullochs usually do have decent spark. The ignition systems are pretty good. I find 90% of the time, provided nobody has tried to fix the saw, they will start doing what you did. Lately I have had more success with so called non-running saws than so called runners. It's amazing the things people do to them!

 

[matt_lamb_160]

Mass panic at the Kern ranch. Went to cut the other day and my favorite 700 quit. Started great like normal, set it down to warm up for a second and it just suddenly died like someone hit the switch. No stumbling around , loading up or anything just purring nicely one second, dead as a door nail the next. Hasn't even tried since.
Not had time to pop covers off but I'm praying for a grounded out coil wire or something easy. I love that saw!

Last time that happened to me, it was just the spark plug. Caused panic for me too. Was my SP81

 

[matt_lamb_160]

Jethro - the Super 250 used the flat back (Walbro MAC) carburetor with a choke. Some folks will complain that they unreliable but in fact I think they perform better than the Tillotson HL although they do seem to be more sensitive to adjustments, particularly on the H setting.

I find them to be more reliable when in a well used state than the Tillotson too. I am a fan of the choked version, even the primer versions are typically OK.

 

[heimannm]

I don't have an actual measurement, but judging by the way the keyway chips and shatters, I would guess in excess of Rc65. It is possible that the center is softer, but drilling and tapping will still be a challenge. On the 1-75 I took apart yesterday...apparently there were two left on the planet, this one appears to have been operated with an overheated clutch or clutch bearing.



Actually I have a few NOS 57756/58128 crankshafts in the attic but some have some light rust from being stored carelessly over the years. These fit the Super series engines, I don't know if they match up with the S250 block as well.

Mark

 

[edju1958]

I must have the other of the 2 left on the planet of the 1-75s,Lol.I had mine running 4 yrs.ago,but there was an issue with the pawls not being tight enough on the clutch.The plate they put on to cover the spring made it next to impossible to work on.The clutch has to be disassembled to put new rivets in or even tighten up the old rivets.
I don't know how it worked (in theory it shouldn't have),but I put a recoil on from a 1-70 to pull it over & start it.I'll say this much - it's one helluva heavy beast!

 

[bob kern]

Last time that happened to me, it was just the spark plug. Caused panic for me too. Was my SP81

That would be awesome!

 

[edju1958]

OK guys,thanks for the help on getting the spring clip in on the oil pump on a PM 10-10.It took some doing & cursing the ancestors of the brilliant engineers who came up with that concept.My theory has always been "if it ain't broke don't fix it".I guess it was to be able to swap out an oil pump without having to pull the tank handle.

Now for my next feat,how do I install the OPL?I need to know how it interlocks with the throttle trigger.I've never had one apart before.I do know that it goes in from the bottom of the handle.

 

[Jethro 2t sniffer]

I don't have an actual measurement, but judging by the way the keyway chips and shatters, I would guess in excess of Rc65. It is possible that the center is softer, but drilling and tapping will still be a challenge. On the 1-75 I took apart yesterday...apparently there were two left on the planet, this one appears to have been operated with an overheated clutch or clutch bearing.

View attachment 1087239

Actually I have a few NOS 57756/58128 crankshafts in the attic but some have some light rust from being stored carelessly over the years. These fit the Super series engines, I don't know if they match up with the S250 block as well.

Mark

Well I'll find out after the weekend. If it won't drill nicely then it's welding time. I even considered getting it running and grinding the welded lump to round and correct size as if in the lathe. It doesn't need to be bang on perfect to thread it. Of course still a danger it will just twist off like cheese after all done

 

[Maintenance supervisor]

OK guys,thanks for the help on getting the spring clip in on the oil pump on a PM 10-10.It took some doing & cursing the ancestors of the brilliant engineers who came up with that concept.My theory has always been "if it ain't broke don't fix it".I guess it was to be able to swap out an oil pump without having to pull the tank handle.

Now for my next feat,how do I install the OPL?I need to know how it interlocks with the throttle trigger.I've never had one apart before.I do know that it goes in from the bottom of the handle.

They are probably one of the easiest opl I have ever taken apart and put together.
It all hinges on the roll pin in the handle, so if you use a nail or punch to hold it together and drive the pin in from the opposite side it goes pretty smoothly.

 

[flatsfisher]

Not strictly a McCullch thing, but I bought this "surface preparation tool" from our local HF a few weeks ago. This unit is an absolute miracle tool for reburbishing chainsaw bars.

View attachment 1081259

One minute later

View attachment 1081260

You have to get them out of the sunlight to really see how they look.

View attachment 1081261

The 40 grit drum is just right for achieving the brushed finish, and I've done 10 or so bars with this wheel so far. At a cost of $30 per drum and figuring I'll get 8-10 more bars at least with this one making it a very cost effective proposition.

View attachment 1081262

Mark

I've been eyeballing this tool for quite a while after seeing various folks' comment about it online. your opinion tipped me over. was driving past harbor freight and saw they were having their parking lot sale. $99.00. seems like a great addition to the metal working corner of my shop.

 

[edju1958]

They are probably one of the easiest opl I have ever taken apart and put together.
It all hinges on the roll pin in the handle, so if you use a nail or punch to hold it together and drive the pin in from the opposite side it goes pretty smoothly.

So how does the spring come into play?

 

[edju1958]

Well I'll find out after the weekend. If it won't drill nicely then it's welding time. I even considered getting it running and grinding the welded lump to round and correct size as if in the lathe. It doesn't need to be bang on perfect to thread it. Of course still a danger it will just twist off like cheese after all done

Jethro,my biggest fear of you welding on a crankshaft is the amount of heat that'll be generated.Might burn up the crank seals?

 

[edju1958]

I bought a Super 2-10 on FB the other day for $50.I don't know much about it other than I'm supposed to get it tomorrow.I had 2 2-10s,but one of 'em got stolen a few yrs.ago.People are retarded when they steal stuff,it didn't even have a carb in it.

 

[Maintenance supervisor]

So how does the spring come into play?

I'll have to try to find a picture of it or see if I have one currently disassembled, but the spring leg catches in the side on the lever and just holds it up.

 

[Squareground3691]

New edition to the McCulloch family, she’s got something special under the hood ,

 

[heimannm]

Ed - See if this helps at all. Do you have that spring (Item 9, 92154)?



Mark

 

[edju1958]

I played around with the OPL today & I think I've got it in right.I'll know more after I get the carb in possibly tomorrow.All that's left to do on the PM 10-10 is the front handle,carb install,& the recoil.I was going to put an SDC37 on it,but decided not to as I'd have to drill a gaping hole in the air box to access the needles.I opted instead to put the SDC65 back in that came on the saw originally,no rebuild necessary & it holds pressure just fine.

I also got the Super 2-10 late today & didn't have much time to go through it.I did find that it doesn't have spark & the compression seems to be low.The chain was adhered to the bar (saw was shipped with bar & chain on it due to being seized on) & I had a helluva time getting it off.I had to put the heat gun on the FW cover screws & beat on them to get them loose.The linkages on the carb are free,& the manual oiler works.My first thing I want to do is get spark back & then go from there.