New guy needs a chain.

[biggerstaff94]

Howdy all, im Kevin, im not an arborist, im a machinist from the NE corner of Indiana. I have a couple saws for harvesting firewood, but ive also got a couple saws i just find cool that i dont use much but are ready to go. Anyway i picked up a MAC 110 because it looked cool and was $10 at a garage sale. Plus top handles are handy once in a while.

Today i took it all apart, cleaned it up, ran the carb through the ultrasonic, and threw it back together.

Anyway, my problem is, it didnt have a chain. Im seeing some things that say its a 1/4 pitch, some things saying 3/8 pitch, i didn’t even think to look at the sprocket while it was apart. Its got the original 10” McCulloch bar and its in great shape so im going to run that. Can anyone give me an Oregon PN for a chain that works with this?

 

[TRTermite]

Post a pic or any numbers that are on the bar and you will get faster/better replies. It could be either chain (I think) on that saw. The 3/8" will be a Low pro chain

 

[Philbert]

Welcome to A.S.!

Some saws came with one size chain, but get changed to another over time.

Clear photos of the current chain, along with any markings would help. *(Oops! Just re-read your post and realize you don’t have a chain).

‘Pitch’ is measured as the distance between the center point of any 3 rivets, divided by 2. As a machinist, this may make sense to you.

1/4” pitch = 0.25”. But 3/8” pitch = 0.365”, because it is nominal.

‘Gauge’ is the thickness of the drive links at the bottom. There may be some wear, but typically gauges are: 0.043”, 0.050”, 0.058”, and 0.063”.

Pitch, gauge, and the number of drive links determine if a chain will fit your saw.

*Since you don’t have an existing chain, an easy thing to do is take the saw to a good saw shop, and buy your first chain from them. They will set you up with the right size.

Philbert

 

[Philbert]

You can also try here to get the original chain specification:

https://www.oregonproducts.com/en/part-finder
Philbert

 

[biggerstaff94]

Post a pic or any numbers that are on the bar and you will get faster/better replies. It could be either chain (I think) on that saw. The 3/8" will be a Low pro chain

Yeah i checked, theres no numbers on the bar.

Welcome to A.S.!

Some saws came with one size chain, but get changed to another over time.

Clear photos of the current chain, along with any markings would help. *(Oops! Just re-read your post and realize you don’t have a chain).

‘Pitch’ is measured as the distance between the center point of any 3 rivets, divided by 2. As a machinist, this may make sense to you.

1/4” pitch = 0.25”. But 3/8” pitch = 0.365”, because it is nominal.

‘Gauge’ is the thickness of the drive links at the bottom. There may be some wear, but typically gauges are: 0.043”, 0.050”, 0.058”, and 0.063”.

Pitch, gauge, and the number of drive links determine if a chain will fit your saw.

*Since you don’t have an existing chain, an easy thing to do is take the saw to a good saw shop, and buy your first chain from them. They will set you up with the right size.

Philbert

Its a .050 gauge, my .06 gauge block doesnt fit. I pulled the cover when i got home, the sprocket spacing looks like its probably a 3/8 chain. .325 wasnt really a thing on these was it?

 

[TRTermite]

Yeah i checked, theres no numbers on the bar.
View attachment 1004569View attachment 1004571

Its a .050 gauge, my .06 gauge block doesnt fit. I pulled the cover when i got home, the sprocket spacing looks like its probably a 3/8 chain. .325 wasnt really a thing on these was it?

Not enough pony power to pull .325" , You have a hard nose Bar so drive sprocket will determine your pitch.

 

[Rocker59]

I think all of the Mac 100 series came with 3/8LP as default. But yours could have been changed at some point in time. Try taking the clutch cover / flapperdoodle chain brake combo off and flipping it over so you can see the underside. Take a sharpie and mark a tooth on the sprocket. Then you can rotate the clutch and count teeth. 6 is 3/8LP, 8 is 1/4. If you have the McCloverleaf sprocket, same routine, just count the slots.

 

[biggerstaff94]

I think all of the Mac 100 series came with 3/8LP as default. But yours could have been changed at some point in time. Try taking the clutch cover / flapperdoodle chain brake combo off and flipping it over so you can see the underside. Take a sharpie and mark a tooth on the sprocket. Then you can rotate the clutch and count teeth. 6 is 3/8LP, 8 is 1/4. If you have the McCloverleaf sprocket, same routine, just count the slots.

Thanks! Its 3/8.

Not enough pony power to pull .325" , You have a hard nose Bar so drive sprocket will determine your pitch.

I thought it took more to pull a 3/8 than .325? I like to learn things if you dont mind explaining.

 

[farmer steve]

@ray benson. Have any manuals Ray that might have chain info in them for this guys saw? Thanks. FS.

 

[Bubster]

If I am not mistaken,make sure you get a 3/8 LP,because there is a slight difference in pitch than standard 3/8.I have heard or read that somewhere a few times,and it may or may not be false info.My first saw was a 110,came with a 10",14",and 16" bar. My 13 year old self was tickled to death,it beat the old bow saw I had been using.

 

[Philbert]

Remember that 3/8 low profile (or ‘Picco’) is different from ‘full-sized’ 3/8 pitch. You likely have 3/8 low profile chain.

Philbert

 

[biggerstaff94]

Does anyone even make a full size 3/8 chain in a 10” loop? I ordered a lp by the way.

 

[Philbert]

Does anyone even make a full size 3/8 chain in a 10” loop? I ordered a lp by the way.

Anything is possible. Chain is manufactured in an endless string, then broken into 25’, 50’, and 100’ reels, or into different loop lengths, for sale. Good shops will make any loop you want / pay for off a reel.

With some basic tools, loops or lengths can be ‘broken’ and ‘spun’ (joined) to lengthen, shorten, repair, etc.

Guys on sites like this do it for stranger reasons!

Philbert

 

[Bubster]

Anything is possible. Chain is manufactured in an endless string, then broken into 25’, 50’, and 100’ reels, or into different loop lengths, for sale. Good shops will make any loop you want / pay for.

With some basic tools, loops or lengths can be ‘broken’ and ‘spun’ (joined) to lengthen, shorten, repair, etc.

Guys on sites like this do it for stranger reasons!

Philbert

10 inch square grind on an 090.I would love to see that.

 

[Philbert]

Pole saws, and some specialty saws use small loops. Chainsaw carvers use some special tools. We have had guys remove all the spaces between cutters (‘full house chain’) just to see how it cut.

Stuff you do over a long winter.

Philbert

 

[biggerstaff94]

Anything is possible. Chain is manufactured in an endless string, then broken into 25’, 50’, and 100’ reels, or into different loop lengths, for sale. Good shops will make any loop you want / pay for.

With some basic tools, loops or lengths can be ‘broken’ and ‘spun’ (joined) to lengthen, shorten, repair, etc.

Guys on sites like this do it for stranger reasons!

Philbert

Yeah ive seen those for sale but i don’t cut enough to justify a spool. I just keep 2 or 3 chains for each saw in my saw box. I just file up what i used after I’m done for the day, its worked for me so far so i just buy loops. I like Oregon full chisel but pickins are slim for 10” 3/8 .050 lp it seems.

Also im pretty sure i would have to pull the clutch off or pull the engine out of the case to get a full size 3/8 chain on this little mac. I tried to test it with the chain from my 660 and it wasnt even close to fitting between the clutch drum and case lol.

 

[biggerstaff94]

Ive also got a problem with this one.

After the overhaul as soon as it starts it runs wot without touching the throttle. I didnt test vacuum but i put 10psi compressed air to it and i doesnt have an air leak. Has 170psi compression, muffler mod, base gasket delete, polished up the intake, exhaust, and transfers, honed cylinder, new piston. The butterfly in the carb is closed, so naturally it dies in seconds. I rebuilt the carb with a genuine walbro kit twice now. Ive never needed to buy a carb kit with my ultrasonic cleaner until this saw so somethings up. The idle screw is turned 1 turn in after it starts engaging the throttle, the hi and lo are 1.5 turns out.

Also i should mention ive never seen this saw run right. I got it from the trash with a scored P&C and no bar or chain. All the gaskets are new, the crank seals are not but dont bubble with 10psi and soapy water. Its got me stumped.

 

[Philbert]

Sorry: I’m a chain guy. But that bar looks awfully long for a top handled saw!

Philbert

 

[biggerstaff94]

Sorry: I’m a chain guy. But that bar looks awfully long for a top handled saw!

Philbert

Its a little front heavy lol. But i had it on hand and the oil holes line up. It was a spare 16” for a husqy 136 i used to have. Its not horribly balanced with a full tank of fuel but ideally it would have a 14.

 

[J D]

Ive also got a problem with this one.
View attachment 1004614After the overhaul as soon as it starts it runs wot without touching the throttle. I didnt test vacuum but i put 10psi compressed air to it and i doesnt have an air leak. Has 170psi compression, muffler mod, base gasket delete, polished up the intake, exhaust, and transfers, honed cylinder, new piston. The butterfly in the carb is closed, so naturally it dies in seconds. I rebuilt the carb with a genuine walbro kit twice now. Ive never needed to buy a carb kit with my ultrasonic cleaner until this saw so somethings up. The idle screw is turned 1 turn in after it starts engaging the throttle, the hi and lo are 1.5 turns out.

Also i should mention ive never seen this saw run right. I got it from the trash with a scored P&C and no bar or chain. All the gaskets are new, the crank seals are not but dont bubble with 10psi and soapy water. Its got me stumped.

What's your process for starting it?
Can you keep it running by feathering the throttle?
Have you checked the fuel line, they're particularly long on those & prone to failing.
The oiler is crankcase pressure driven & has a little one way duckbill valve between the crankcase & oil tank. If that fails you may not be getting enough impulse to properly draw fuel up that long line. A pressure test wouldn't necessarily pick that up either unless you had the oil tank empty & the cap off