McCulloch Mini and Small CC Chainsaw's
- Thread starter Overtrained
- Start date
Help Support Arborist Forum:
bikemike
loud pipes save lives
Sold my old 341 early spring. If your looking for a little more pep in those reed port saws the intake end of them is a great start
Hi Guys
No expert here....but I think I saw that a mini mac 6A is a little piston port engine. All my current small top handle saws are reed valve type. Would anyone who has tried more saws than me give an impression if the MM6A feels or runs better/worse/different from homelite XL2, poulan D25 or micros, small CS-280EP Echo, small 015L stihl all being reed valve?
My friend has several saws, all rear handle, and I suggested he might enjoy a top handle. He gave me a rough Mini Mac 6 to fix up for him. I can stand a challenge.... if it is worth it...
TIA
No expert here....but I think I saw that a mini mac 6A is a little piston port engine. All my current small top handle saws are reed valve type. Would anyone who has tried more saws than me give an impression if the MM6A feels or runs better/worse/different from homelite XL2, poulan D25 or micros, small CS-280EP Echo, small 015L stihl all being reed valve?
My friend has several saws, all rear handle, and I suggested he might enjoy a top handle. He gave me a rough Mini Mac 6 to fix up for him. I can stand a challenge.... if it is worth it...
TIA
If the piston and cylinder are in good shape and the rings are not too worn, the MM6 has some pep. They are not a good firewood saw and the top handle arrangement is really not that convenient for bucking. You will find that using the saw one handed you tend to press your little finger on the top of the saw housing...and they do get warm.
Mark
Mark
I acquired an Echo CS-310 and find it a very nice little saw. Oiler only works when the clutch is turning, bit special on a cheap saw. I put a 16" bar on but a 14 might be better.
It does not take many tools to disassemble a Mini Mac. Later models with the removable starter are certainly easier but if you realize you have to align the fins on the flywheel with the starter pawls on the way out and back in again it is a lot easier.
Most of the fasteners that hold the saw together are pretty obvious. A few that sometimes escape your attention are the one behind the AF...
Believe it or not, the choke knob...
And the white plastic tab on the bottom of the saw that holds the fuel line in place...
And now it is apart. From start to this point took me about 40 minutes.
Mark
Most of the fasteners that hold the saw together are pretty obvious. A few that sometimes escape your attention are the one behind the AF...
Believe it or not, the choke knob...
And the white plastic tab on the bottom of the saw that holds the fuel line in place...
And now it is apart. From start to this point took me about 40 minutes.
Mark
There were many, many variations of the MM over the years, chrome bore with plain pistons, plated pistons with plain bore, and open and closed port configuration, and either two bearings in the piston with the pin pressed in place, or one bearing in the rod with cir-clips to hold the rod in the piston. There were also a lot of differences in the covers, early ones had a short clutch cover with no brake, later ones had a short clutch cover with a brake, and later still had long clutch covers that also cover the muffler. A few models (155, 165) also had a longer rear handle that made them look more like a two handed saw. Fentimac (Eberhard) has a nice 165 in some of his photos, I don't think I have one in the attic but I will take a look.
This particular saw was a chrome plated piston but most of the chrome is gone.
The plain aluminum bore was pretty rough as well, particularly from the carbon coming off around the exhaust ports. This one (110) happened to be a closed port. I will try to remember and get some photos down the bore of a couple later on.
This particular saw was a chrome plated piston but most of the chrome is gone.
The plain aluminum bore was pretty rough as well, particularly from the carbon coming off around the exhaust ports. This one (110) happened to be a closed port. I will try to remember and get some photos down the bore of a couple later on.
Here are a couple more shots of the worn plating on the piston.
Notice that both bearings in the piston are "closed end" type. This is different from many of the large frame saws with a close bearing on the exhaust side and open bearing on the opposite side. So, how do you get the wrist pin out with two closed bearings?
Just punch through the shield on one end and push it out. The brass punch is just for show, I used the 1/4" socket head cap screw in place of a 1/4" drift punch to punch through the shield and push the pin out.
Mark
Notice that both bearings in the piston are "closed end" type. This is different from many of the large frame saws with a close bearing on the exhaust side and open bearing on the opposite side. So, how do you get the wrist pin out with two closed bearings?
Just punch through the shield on one end and push it out. The brass punch is just for show, I used the 1/4" socket head cap screw in place of a 1/4" drift punch to punch through the shield and push the pin out.
Mark
I did not reuse this piston, but if you do reuse a piston it will be necessary to push out the carcass of the remaining bearing.
The job is easier if you have a few tools.
Mark
The job is easier if you have a few tools.
Mark
Since the cylinder I used for this rebuild I was able to use a plain (non plated) piston. 68098 was originally used in the PM6 saws and was also used on many later Mini Mac saws as well.
This one came with one bearing installed, but you can press both in if you need to, just make sure you don't press it too far. Again, having a few special tools helps.
It is a little tricky to hold the connecting rod in just the right spot when pressing the pin in, but the slight chamfer on the ends of the wrist pin help get everything lined up and started. There is a special driver that you use to get the pin pressed into the proper position, but I forgot to get a photo of that part of the operation. Once the pin is in, the second bearing goes on again using the special tool to make sure you don't press it too far.
Mark
This one came with one bearing installed, but you can press both in if you need to, just make sure you don't press it too far. Again, having a few special tools helps.
It is a little tricky to hold the connecting rod in just the right spot when pressing the pin in, but the slight chamfer on the ends of the wrist pin help get everything lined up and started. There is a special driver that you use to get the pin pressed into the proper position, but I forgot to get a photo of that part of the operation. Once the pin is in, the second bearing goes on again using the special tool to make sure you don't press it too far.
Mark
New cylinder, new piston, new rings, but it never hurts to check the end gap...you don't want it to warm up and have the rings expand and close up tight. I don't remember the range exactly but I think the book says 0.004" to 0.012" is acceptable.
If the gap is a bit too small, I like to clamp a flat file in the vice then work the ring ends against it trying to keep everything nice and square. These were right at 0.005 to 0.006". Most of the time the rings have no identifying marks, but these had a couple of dots, make sure to install them with the dots up towards the top of the piston.
Next step is to work the piston into the bore, since the rings are not pinned in this model I set them about 120º apart trying to avoid putting them in the intake or exhaust ports.
I had had very good success using Threebond 1184, a light coat on both halves before assembly. I tried to locate the bearings in their final resting spot, but pull the seals out just a bit so I can square and flush them once the block halves are together. It should be possible to press the seals in after assembly but some times the edges don't have quite enough chamfer to make that possible, this way I know they are started in the bore so it only takes a touch to finish putting them in position.
Mark
If the gap is a bit too small, I like to clamp a flat file in the vice then work the ring ends against it trying to keep everything nice and square. These were right at 0.005 to 0.006". Most of the time the rings have no identifying marks, but these had a couple of dots, make sure to install them with the dots up towards the top of the piston.
Next step is to work the piston into the bore, since the rings are not pinned in this model I set them about 120º apart trying to avoid putting them in the intake or exhaust ports.
I had had very good success using Threebond 1184, a light coat on both halves before assembly. I tried to locate the bearings in their final resting spot, but pull the seals out just a bit so I can square and flush them once the block halves are together. It should be possible to press the seals in after assembly but some times the edges don't have quite enough chamfer to make that possible, this way I know they are started in the bore so it only takes a touch to finish putting them in position.
Mark
Blisters - If all you have to do is remove the chain and clean up the chain and bar, is should be easy enough. A lot of guys don't want to tear into a Mini Mac since you have to take the engine out of the housing to do anything with the carburetor or ignition.
The same screws are used to hold the coil and the carburetor in place. There are two insulator sleeves and insulating washers on the coil; I guess this is to help keep the heat of the coil from adding to vapor lock issues. The carburetor is also installed with an insulator between the cylinder and the carburetor.
Don't forget that seal one the crankshaft before you install the points cover, it is the only thing that keeps sawdust out of the ignition.
The saw was designed so that you installed the engine into the housing, then put the fuel/oil tank in place pressing the oil and fuel line home. I prefer to assemble the tank to the engine out of the block, then assemble the whole works into place. This is much easier to accomplish with the more modern saws with the removable starter.
When you do, make sure the oil lines end up in the right places. The little "T" line fits into the boss on the front of the bar mount and to the inlet of the automatic oil pump (red line). On manual oiler only models this line goes directly to the back side of the bar mount. The outlet from the automatic oil pump has another line that goes from the pump to the receptacle on the back side of the bar mount (blue line). It is a lot easier to see all this with the engine out of the housing.
Mark
The same screws are used to hold the coil and the carburetor in place. There are two insulator sleeves and insulating washers on the coil; I guess this is to help keep the heat of the coil from adding to vapor lock issues. The carburetor is also installed with an insulator between the cylinder and the carburetor.
Don't forget that seal one the crankshaft before you install the points cover, it is the only thing that keeps sawdust out of the ignition.
The saw was designed so that you installed the engine into the housing, then put the fuel/oil tank in place pressing the oil and fuel line home. I prefer to assemble the tank to the engine out of the block, then assemble the whole works into place. This is much easier to accomplish with the more modern saws with the removable starter.
When you do, make sure the oil lines end up in the right places. The little "T" line fits into the boss on the front of the bar mount and to the inlet of the automatic oil pump (red line). On manual oiler only models this line goes directly to the back side of the bar mount. The outlet from the automatic oil pump has another line that goes from the pump to the receptacle on the back side of the bar mount (blue line). It is a lot easier to see all this with the engine out of the housing.
Mark
Blisters
ArboristSite Operative
Holy crap batman! Well if it's not too bad... I know it's got carb issues. I might just give it a shot and see how it gos. If it don't y'all can get the parts.
Before you put the automatic oil pump together, make sure it is correctly assembled and that it is working. There is one check valve in the top of the pump housing that is not accessible or serviceable so making sure not will avoid having to pull the front off the housing and removing the fuel/oil tank to change it later. The empty hole is the inlet, the one with the tube sticking out of it is the outlet to the bar. Put a drop or two of oil in the inlet hole and work the piston manually a few times, you should see the oil oozing out the discharge tube. The o-ring seal at the base of the automatic oil pump is a standard 020 o-ring, 1" O.D. and 7/8" I.D. They will cost $5.00 to $10.00 each if you buy them by the McCulloch part number 110653 off e-bay, or $0.50 to $1.00 or so each if you buy them from a bearing/hose shop, or $4.50 for 100 pieces from McMaster Carr + $6.00 for shipping.
The pump parts in order: pump body, adjuster sleeve, spring, piston assembly, and the o-ring seal.
The sleeve will only fit one way into the pump body and allow you to actually adjust the flow.
At this point I stopped taking photos, but reassembly is pretty straight forward. The biggest problem I have every time is getting the throttle rod reconnected. I find it is easier for me to remove the spring and take the throttle trigger and arm off the saw and get it connected, then reassemble the trigger to the housing and reconnect the spring. Your experiences may be different.
The little saw started right up and with a bit of adjustment would idle, rev, and oil as it should. I handed the saw back to the owner, we'll see if he can eventually come up with the $110 I had in parts.
Mark
The pump parts in order: pump body, adjuster sleeve, spring, piston assembly, and the o-ring seal.
The sleeve will only fit one way into the pump body and allow you to actually adjust the flow.
At this point I stopped taking photos, but reassembly is pretty straight forward. The biggest problem I have every time is getting the throttle rod reconnected. I find it is easier for me to remove the spring and take the throttle trigger and arm off the saw and get it connected, then reassemble the trigger to the housing and reconnect the spring. Your experiences may be different.
The little saw started right up and with a bit of adjustment would idle, rev, and oil as it should. I handed the saw back to the owner, we'll see if he can eventually come up with the $110 I had in parts.
Mark
The 130 has the removable starter, just remember to remove all of the fasteners including the choke knob and pop the fuel fitting tab loose before you pull the engine out of the housing. Disconnect the throttle too...
If you come up with a slick way to reconnect the throttle please let us know.
Mark
If you come up with a slick way to reconnect the throttle please let us know.
Mark
Blisters
ArboristSite Operative
Never ran or worked on a Mac. Just homies and poulans mainly. This sounds like an event.
I got home today from the PNW GTG over the weekend and found this box of parts waiting, thanks Brian.
Mark
Mark
joeymt33
I bleed YELLOW!
Hey Mark, it's been a long time.
What did you do to make it Brian mad?
Sent from my iPad 7G
Blisters
ArboristSite Operative
I am looking at a pro Mac 10-10s the man wants me to make him an offer. The saw won't crank cause it has set for several yrs. It's got good compression and looks to be used very little. 20 in and 28 in bar come with. What do y'all think it is worth?
Similar threads
Latest posts
-
-
-
-
-
Please recommend a small chipper- Boxer x7 vs Vermeer bc700xl or....- Latest: Crftrapper535
-