McCulloch Chain Saws

[heimannm]

1-50 would have the Lubri-Mac system that directs the crankcase residue to the bar for lubrication, could be it is working as it should...

The fuel tank vent is also in the vicinity (item 31), should be possible to remove it and clean it out. The fuel cap on that model is not vented.



Mark

 

[ML12]

Update on the rough looking 7-10 I picked up. It was full of water (had been sitting outside last week during the rainstorm we had here). I sprayed it full of WD-40 and spun it over a bunch, lots of water came out. Cleaned up the decompression valve and what do you know? arm breaking compression, rolls over nice and smooth. I think i'll have a great runner!

Also, the bar is 24" mcculloch stamped with a like new chain. I'm stoked!

 

[Jethro 2t sniffer]

Update on the rough looking 7-10 I picked up. It was full of water (had been sitting outside last week during the rainstorm we had here). I sprayed it full of WD-40 and spun it over a bunch, lots of water came out. Cleaned up the decompression valve and what do you know? arm breaking compression, rolls over nice and smooth. I think i'll have a great runner!

Also, the bar is 24" mcculloch stamped with a like new chain. I'm stoked!

Sometimes the ugly ones go the best my ugly 1 does haha. And sorry it's not ugly at all I love them battle scared gives a real character to them

 

[Goinwheelin]

I like the patina of the chipped up ones. Makes it kinda like a rat rod lol.
Should have this 7-10 done tonight. Had a minor setback by accidentally putting the pto side bearing in with the seal facing the wrong way. Had to crack the case open again. This is the one I polished the piston on and installed NoS rings.

 

[Jethro 2t sniffer]

I like the patina of the chipped up ones. Makes it kinda like a rat rod lol.
Should have this 7-10 done tonight. Had a minor setback by accidentally putting the pto side bearing in with the seal facing the wrong way. Had to crack the case open again. This is the one I polished the piston on and installed NoS rings.
View attachment 795817

That looks mean and the muffler too. What cool looking saw. Definitely rat rod style

 

[mogulmasher]

7-10 transfers
View attachment 795758 View attachment 795759

Looks just like pm700 without the bridge. So maybe that bridge can be removed for better performance with the pm700. Wonder why the bridge was added since the pm700 was a later design than 7-10? Increase engine life? Help keep rings from catching port?

 

[vinnywv]

As ive torn into the sp70 the transfers are like those on the 700. They have a bridge also. Its very interesting, thanks for all the pictures though.

 

[mogulmasher]

As ive torn into the sp70 the transfers are like those on the 700. They have a bridge also. Its very interesting, thanks for all the pictures though.

Interesting, I thought the sp70 would have the 3 finger ports like my cp70. Sounds like the cp70 has transfers different than all the other 10 series 70cc saws.

 

[vinnywv]

 

[PogoInTheWoods]

As ive torn into the sp70 the transfers are like those on the 700.

What style piston?

 

[PogoInTheWoods]

Interesting, I thought the sp70 would have the 3 finger ports like my cp70. Sounds like the cp70 has transfers different than all the other 10 series 70cc saws.

Without going through the IPLs in detail, I'm gonna go out on a limb here based on the pics provided and suggest the CP70 simply has the divider like the PM700 and SP70. Can't see em using a completely different design on just one saw, especially since they seem to list the same piston for all of them except the early ones (if I recall correctly). I'd hafta dig back through some notes to compare the piston numbers across the 70cc platform over the years.

 

[vinnywv]

What style piston?

its a trashed thin ring piston. The boot tore and it went from there. Atleast thats my assessment

 

[2broke2ride]

Just purchased a 1-50. Turns over quickly and runs strong. Problem is that its leaking fuel at the oiler, where that small hole is on the left side. Anything go there like a duck bill or what? I will have to drill out the fuel vent since it is seized and will not thread out. Any input would help, was just about to open her up either way and figure it out but seems like this may be a common issue. Checked the parts diagram and seems like there is nothing that goes in that hole? I'm thinking since that vent needs to be replaced, the tank isn't breathing and making the fuel dump out. Let me know guys, thanks.

Just so happens that I just picked up a 1-50. There should be a plastic tube inside the tank connected to that port. It runs to the top of the tank. If yours is missing it would leak anytime you where over half a tank nm I would think. It is number 30 in Mark's diagram. You can see it looking in the fuel cap.

 

[PogoInTheWoods]

its a trashed thin ring piston. The boot tore and it went from there. Atleast thats my assessment

Bummer. Was interested in whether it was windowed or what I call a 'port hole' style. Seems as though the windowed pistons and divided transfers commonly go with one another. And is it my imagination or is the skirt on one side slightly longer than the other?

Thanks for posting the pic, btw.

 

[vinnywv]

I think thats an illusion but i threw it away and its garbage night. Im not going back out for that. Sorry. Incidentally i do have a piston for the 82cc saws. I measured its skirting and its the exact length on both sides. At 1.742" , id guess the 70cc are the same but when i get the new one in a couple weeks, ill be sure to measure it for you.

 

[mpatch]

Any idea what a 1-72 is worth? For it's age it's pretty damn clean, not missing any parts, doesn't look like it's seen a whole lot of use. Seems to have decent compression. It's been sitting for a few years at least, guessing at a minimum it needs a carb kit.
I can post some pics later if that would help.

 

[PogoInTheWoods]

I think thats an illusion but i threw it away and its garbage night. Im not going back out for that. Sorry. Incidentally i do have a piston for the 82cc saws. I measured its skirting and its the exact length on both sides. At 1.742" , id guess the 70cc are the same but when i get the new one in a couple weeks, ill be sure to measure it for you.

No biggie. Was just curious. Somewhere in the back of my mind is an image of non-symmetrical skirts on a Mac piston. Maybe the port hole style? A lot of clutter back there, tho. I could be thinking of who the hell knows... LOL

 

[Maintenance supervisor]

I like the patina of the chipped up ones. Makes it kinda like a rat rod lol.
Should have this 7-10 done tonight. Had a minor setback by accidentally putting the pto side bearing in with the seal facing the wrong way. Had to crack the case open again. This is the one I polished the piston on and installed NoS rings.
View attachment 795817

Are you going to run this saw? I mean like work it , or is it a piece of your collection?
I have saws that don't go to work with me so no offense intended .

 

[kbeck]

I think thats an illusion but i threw it away and its garbage night. Im not going back out for that. Sorry. Incidentally i do have a piston for the 82cc saws. I measured its skirting and its the exact length on both sides. At 1.742" , id guess the 70cc are the same but when i get the new one in a couple weeks, ill be sure to measure it for you.

I think thats an illusion but i threw it away and its garbage night. Im not going back out for that. Sorry. Incidentally i do have a piston for the 82cc saws. I measured its skirting and its the exact length on both sides. At 1.742" , id guess the 70cc are the same but when i get the new one in a couple weeks, ill be sure to measure it for you.

No biggie. Was just curious. Somewhere in the back of my mind is an image of non-symmetrical skirts on a Mac piston. Maybe the port hole style? A lot of clutter back there, tho. I could be thinking of who the hell knows... LOL

No some are different just tore my Pro Mac 60 apart after I pressed the pin out of the piston I noticed one skirt shorter not just alittle either
Should have been paying attention but I think the shorter skirt is intake side can't see a shorter exhaust side doing anything. neither my old or new piston
has a ex marking. Anyone know for sure?

 

[Maintenance supervisor]

View attachment 795916


No some are different just tore my Pro Mac 60 apart after I pressed the pin out of the piston I noticed one skirt shorter not just alittle either
Should have been paying attention but I think the shorter skirt is intake side can't see a shorter exhaust side doing anything. neither my old or new piston
has a ex marking. Anyone know for sure?

I can try and peek down the intake of mine this weekend, if its shorter on the intake side should be able to see that.