MCCULLOCH The official McCulloch thread

[Al Smith]

The only way to punish those people who put a flatty on anything is to dig them up and grind their bones .I've only got one, a Super 44A .That said after nearly having to make love to it the saw for as old as it is does scoot .

 

[Lee H]

Al -

It's the stock carb for the non-super 797. I think it's a pretty decent carb and probably easier to deal with than the Flatback carbs of that era.

Jacob the 103 is actually the carb used on the early Super 797's and a few other Mac's.

 

[Al Smith]

On those old Macs from just looking at IPL's it appears I think the 797 is more closely related to a 101 kart engine than is a 125 chainsaw .If my info is correct either the Super 44A or the 1-70 became the MC 10 kart engine . If course in those days a zillion companies made after market parts for them to get a little more zip . I might say the 87's with a removable head or not are my favorites of all the reed valve engines .They got that one right .

 

[edju1958]

After dumping a little Seafoam in the fuel tank yesterday on my PM10-10,I ran it for a bit & let it sit overnight.I took it out with me cutting today - mistake.I've never seen a saw do this - it runs fine on the start up & for the first few minutes.Then it starts to bog down like it's getting too much fuel.It never leans out,so I'm leaning toward a carb issue.From what I can see it has an SDC65.I think I put a new fuel filter on it when I got it last fall.I'll pull the casrb over the next couple days & go through it.I also bought another SDC65,not for this saw though.Wondering also if the condenser could be going bad?

 

[heimannm]

Ed - Check the metering lever height, and make sure the needle and seat are sealing properly.

Mark

 

[bobdeaton@ hotmail.com]

Can I ask a 10-10 question here ? I am rebuilding my first one.

 

[Steve]

Can I ask a 10-10 question here ? I am rebuilding my first one.

Absolutely!

 

[Al Smith]

What he said ,fire away somebody has rebuilt one

 

[bobdeaton@ hotmail.com]

OK , thanks all ! I have a saw that was marked Mac 10-10 but no tag . Number on bottom is 10 2346 . I just put new rings in it after mild porting . Used caber 45 mm x 1.2 rings and had to trim them slightly to fit cylinder . I ordered a set of 10-10 rings and piston and they were 1.5 thick and would not fit original piston . Then a standard seal kit for 10-10 ordered . Installed small seal no problem. Large seal would not fit . It is 1.5 inch and seal I took out is 1.3 . Do I have a 10-10 ? Next when I install tank handle on cylinder there is a gap between it and rear screw boss on cylinder. Tank is flat on intake / spacer, about 1/4 of inch gap at rear . Am I missing a spacer or something? Thanks for any help !

 

[Steve]

OK , thanks all ! I have a saw that was marked Mac 10-10 but no tag . Number on bottom is 10 2346 . I just put new rings in it after mild porting . Used caber 45 mm x 1.2 rings and had to trim them slightly to fit cylinder . I ordered a set of 10-10 rings and piston and they were 1.5 thick and would not fit original piston . Then a standard seal kit for 10-10 ordered . Installed small seal no problem. Large seal would not fit . It is 1.5 inch and seal I took out is 1.3 . Do I have a 10-10 ? Next when I install tank handle on cylinder there is a gap between it and rear screw boss on cylinder. Tank is flat on intake / spacer, about 1/4 of inch gap at rear . Am I missing a spacer or something? Thanks for any help !

45mm is definitely a 10-10 bore.

Did you get an original piston or a little red barn piston?

You need the national 471551 seal that fits inside the bearing race. The seal you got is for the thin bearing style.

How thick is the cylinder to handle spacer?

Pictures are always helpful.

 

[bobdeaton@ hotmail.com]

Little red barn piston . Spacer plus gaskets is 3/8 ‘s original piston is 1 3/4 inch and rings were 1.3 mm thick . Thanks for seal info I will get it . it does go in the bearing race . The spacer puts front of gas tank 1/8 th above oil tank . Do you think I have an earlier series of saw ? 2-10 maybe ?

 

[Steve]

Little red barn piston . Spacer plus gaskets is 3/8 ‘s original piston is 1 3/4 inch and rings were 1.3 mm thick . Thanks for seal info I will get it . it does go in the bearing race . The spacer puts front of gas tank 1/8 th above oil tank . Do you think I have an earlier series of saw ? 2-10 maybe ?

Take the lrb piston and throw it away. Hope I don't sound too abrasive but those pistons fit poorly and are a literal last resort life or death situation in my opinion.

The thick spacer is correct for your cylinder. ,There should be a thick rubbery fiber gasket on both sides of the cylinder shroud on the bolt in the carb box under the throttle rod. Definitely need pictures. Does your cylinder have a dsp valve or a poppet decompression valve? Or none at all?

 

[bobdeaton@ hotmail.com]

No decomp valve . And no spacer under rear screw. I thought I was missing something and could not find it on Mac 10-10 parts list. I had the same thought about piston kit from lrb . Cabers should work great on original piston I hope . Original top ring was broken and lower broke as I was taking it off. I will take pictures tomorrow and post here. Thank you for info. I got seal ordered as we talked.

 

[Al Smith]

Sounds like more trouble than it's worth .They made the 10-10 for like 25 years and they made a bunch of them .Plus the larger 70 cc models like the 6-10 .700 etc .All the sudden in spite of the numbers made they are worth a lot of money ??I don't claim to be an expert but I've never had one that wore out the bearings but I have changed the seals which are easy to find .Only one had a bad piston and that was because of running rocket fuel /aviation gasoline and 20 percent nitro .Ran like a scalded ape for about 5 minutes then the piston God took it ,clunk .
Somebody will have a piston ,I do but don't want to part with them, sorry .These series will almost run forever before they need rings providing you don't get stingy with the mix oil .
Now then ,parts lists .There most likely are 25 people on this forum or more who have the parts lists including my self .However if you Google "ChainswR " he has the IPL's and you can copy them .
In a nut shell the 10-10 is a good old saw ,not the fastest but very dependable --usually .If you don't abuse them they could probably be passed on to your grand children .You have to have a degree of patience if you ever have a prayer of restoration .Put that thing in a box with all the parts and bide your time .At some time another one will come along .maybe a freebie and you'll have all the parts you'll ever need .BTW good luck

 

[heimannm]

The biggest problem with the LRB pistons is the wrist pin, they simply do not understand that the wrist pin must be a press fit in the connecting rod and the ones supplied with their piston will fall out. Be sure to use the OEM wrist pin and you should be O.K. Some folks have complained about the bearings in the piston but the few LRB pistons that I have seen all had name brand bearings in them.


This illustration shows the insulating washers on either side of the cylinder shroud (Item 57) as well as the spacer under the front of the fuel tank (Item 46). Early models did not have the screw between the oil tank and the fuel tank so there was no spacer there.




Contrary to some opinions, the OEM rings and pistons are getting hard to find. I have plenty of 0.030" oversize rings that can be filed to fit, but the original 62814 rings and 69212 pistons are pretty scarce.

There were two different bearing and seal combinations used on the flywheel side. Most 10-10 models and many other 10 Series as well used the 67905/67906 in which case the seal O.D. matches the bearing O.D. and presses in beside the bearing. Most (but not all) of the bigger displacement saws used the 63429 bearing with the wide outer race and the 61618 seal that presses into the wide outer race of the bearing. You have the correct seal for your saw, but it sounds like someone has replaced the flywheel side bearing with the 63429 in which case you need 61618 which is readily available from several seal manufacturers today. 0.562 shaft x 1.375" O.D.

The full IPL for the 10-10 power head is attached.

Mark

 

[Steve]

Sounds like more trouble than it's worth .They made the 10-10 for like 25 years and they made a bunch of them .Plus the larger 70 cc models like the 6-10 .700 etc .All the sudden in spite of the numbers made they are worth a lot of money ??I don't claim to be an expert but I've never had one that wore out the bearings but I have changed the seals which are easy to find .Only one had a bad piston and that was because of running rocket fuel /aviation gasoline and 20 percent nitro .Ran like a scalded ape for about 5 minutes then the piston God took it ,clunk .
Somebody will have a piston ,I do but don't want to part with them, sorry .These series will almost run forever before they need rings providing you don't get stingy with the mix oil .
Now then ,parts lists .There most likely are 25 people on this forum or more who have the parts lists including my self .However if you Google "ChainswR " he has the IPL's and you can copy them .
In a nut shell the 10-10 is a good old saw ,not the fastest but very dependable --usually .If you don't abuse them they could probably be passed on to your grand children .You have to have a degree of patience if you ever have a prayer of restoration .Put that thing in a box with all the parts and bide your time .At some time another one will come along .maybe a freebie and you'll have all the parts you'll ever need .BTW good luck

Sell the man a piston Al. You know very well you will meet Jesus before you ever use it.

 

[Squareground3691]

Sell the man a piston Al. You know very well you will meet Jesus before you ever use it.

And Jesus will be holding one of these lol

 

[heimannm]

 

[edju1958]

I've done some serious thinking about my PM10-10 & have come to the conclusion that it's not a crank seal gone bad,nor is it a carb issue either.The saw starts fine & idles & throttles up well,until...it gets hot.With a seal it'd lean out as well as bog down.This saw only bogs down.If it were a carb issue it'd have difficulty starting & wouldn't run worth a damn.What's left?I'm now thinking it's a condenser or coiol beginning to break down.When I got the saw the coil was off.I put it back on & all was good,or so I thought.I never got a chance to take it out cutting last fall & it sat all winter.I'll put a chip in the saw & that'll tell me if it's the condenser.If it runs the same,then I'll try changing out the coil.It's like chasing after a ghost,Lol.

 

[Maintenance Chief]

I've done some serious thinking about my PM10-10 & have come to the conclusion that it's not a crank seal gone bad,nor is it a carb issue either.The saw starts fine & idles & throttles up well,until...it gets hot.With a seal it'd lean out as well as bog down.This saw only bogs down.If it were a carb issue it'd have difficulty starting & wouldn't run worth a damn.What's left?I'm now thinking it's a condenser or coiol beginning to break down.When I got the saw the coil was off.I put it back on & all was good,or so I thought.I never got a chance to take it out cutting last fall & it sat all winter.I'll put a chip in the saw & that'll tell me if it's the condenser.If it runs the same,then I'll try changing out the coil.It's like chasing after a ghost,Lol.

High speed check valve could be full of black goo?
Just chip it and eliminate the possibility of the ignition.