McCulloch Mini and Small CC Chainsaw's

[turmlos]

Thanks Mark. I'm very grateful for the McCulloch knowledge you've shared here. It's helped me fix up this saw along with my 10-10A, PM700, and 4600, as well as my old man's 3818. I'd gladly purchase a yellow cover from you if you've got one. Feel free to shoot me a PM when time permits.

 

[piglosi]

I rescued this little guy from my buddy's scrap pile. It was a dirty mess with several parts missing. The cylinder was full of oil and the spark plug hole was stripped out. I went over the oiler and freed up the ball in the check valve. I also Helicoil'ed the cylinder, and consequently the original taper plug would no longer seal. I ended up going with a standard CJ8 plug with a crush washer. I need to modify the rear handle a bit so I can remove the larger plug easily. Of course I rebuilt the carburetor, it had a Zama so I lucked out there. The chain tensioner was missing so I modified a different one I had. She runs great! I may even invest in an uncracked air filter cover. I epoxied the old one for now.

View attachment 1148980View attachment 1148981

Nice little saws when all the bugs worked out of em. I have 2 mac 120’s in the barn I put some time into. They both fired up and ran well this morning at 10 deg.

 

[turmlos]

Mine can't seem to keep bar oil in it for long, leaks out rather quickly. Seems to be a common problem. At least the cylinder isn't filling up now.

 

[heimannm]

If the tank itself is not cracked and leaking, the most common issue is the connector between the tank and the saw. There are two different parts depending on the models, automatic oiler versions use 84613/217167 and manual oiler only 217156.

I just discovered there was a "CP" (Cushion Power) version of the Mini Mac with anti-vibe mounts at the front and rear handles. If anyone happens to have one they want to move along, I would be interested.



This is different from the SP40/PM510/515 type handle. I can't say that I have ever seen one like this.

Mark

 

[turmlos]

Mark,

I triple checked that line but it's not the problem. It seems to dribble constantly from the bar oil hole. Would that indicate a bad check valve? Does the manual oiler plunger use any o-rings/seals?

Todd

 

[heimannm]

There is no check valve and no o-ring(s) in the manual pump itself. On saws with the automatic oiler, the only check valve is in the pulse pump. On the manual oiler only version there is a check valve in the spot where the connector plugs into the tank.

Mark

 

[heimannm]

The "check valve" in the manual only version is shown here as Item 1. It is just a little rubber sleeve that fits in the pocket before the connector plugs into the tank. I will admit I don't actually understand how it works, but I know that it must be there for the manual only to pump oil.



Mark

 

[Gumneck]

To update my post with findings. The Hubbards Spring Co. would have to have an order of 100 to run and they are $2.68 each as they do not have any in stock.

The Mikes carb shop link has 1/2" aluminum but a warehouse person measured and they are thicker than .0302, more like .064. But they are $6.85 for 10. Being aluminum, they should file down much quicker with less blood from my finger tip.

I bought some 1/2" aluminum welch plugs from the mike's carb shop online. Going to try them out on the next minimac 6.



The plug on the far left is the aluminum Mike's carb shop, the middle is a steel McMaster Carr, and the one on the right is the original....all are 1/2".

 

[Gumneck]

This was my first plug removal and install....greenhorn! I just used a small socket with a small ball peen hammer. One solid hit with carb sitting on a bundled up rag. I might not should have used a socket and instead a solid punch?

Need to test it out. Afraid to pull the fuel line off and destroy it possibly.

 

[Gumneck]

On the Minimac 6 does anyone use a fat oring to possibly eliminate any leaks? Seems like an oddball way that it just sits in the tank recess up against the filter and not be a snug fit.

 

[heimannm]

That is an old, old fuel line. The more "modern" version has a fitting with an o-ring that plugs into the tank and allows the use of a more conventional fuel line. The fitting also clips into the housing to keep in in the saw when you pull the fuel/oil tank out.



The fuel line kits are PN 90661. Let me know if you can't find them elsewhere, I have a few still.

Mark

 

[MacAttack]

On the Minimac 6 does anyone use a fat oring to possibly eliminate any leaks? Seems like an oddball way that it just sits in the tank recess up against the filter and not be a snug fit.


View attachment 1160311

You'll want to replace that fuel line with the more modern style that Mark illustrated. My MM 6 had one of those and it didn't have a chance of sealing tight. You need the plastic tank pickup with the O Ring that takes a normal fuel line to the carb

 

[Gumneck]

Thanks for the info guys. On the way.

https://www.ebay.com/itm/2259277857...7h1iR7Vch6VLOhHsoKL7Hh1ho=|tkp:Bk9SR9T-mbjEYw

 

[FixIt20]

Replacing crank bearings and seals to fix a crank seal leak. The vac/pres test leaks very slightly unless pressure is put on the end of the crankshaft. Then it leaks badly. Was wondering how much play there should be where the arrows point to in the picture. Also, is there a good way to know how far in the bearings go in relation to the edge of the cylinder?

 

[heimannm]

You need to position the bearings so they basically hold the crankshaft in the proper centered location. For that reason the bearings will extend into the crankcase a fair bit as your photos show. End play on those can be as much as 0.030-0.040" or more with little ill effect.

Mark

 

[FixIt20]

Is there a easy way to tell when they're centered?

 

[heimannm]

You just have to judge it looking at the connecting rod and crankshaft.

Mark

 

[MacAttack]

I finally decided to tear into my Made in Taiwan MS 1635 McCulloch. New fuel lines and oil line to oil tank, replaced the flywheel which is why the saw was abandoned with VERY little running on it. The plastic recoil pawls were both broken and the threaded hole for the pawl screw was stripped. I have a rough 3818 that I'm cannibalizing for parts, including the flywheel.
Carb diaphragm kit is on the way, this should make a good plastic companion to my Mini Macs. I will be interested to see if it can keep up with my SP 40.

Does anyone happen to know the flywheel/ coil air gap? It's rubbing with the new flywheel, so I was planning to set it to .010"

 

[heimannm]

0.010" is correct for the flywheel to coil clearance.

The 32, 35, 38 cc "plastic" saws were designed in Tucson, most parts were being manufactured in Arizona and assembled in Hermosillo Mexico before Jenn Feng purchased the McCulloch name for North America. Jenn Feng continued to produce those models as they were developing their own design concepts and some of the features of the McCulloch designs carried over to the Jenn Feng models, the styling of the AF cover in particular was retained although they changed the choke mechanism.

3516



Jenn Feng 2050



Mark

 

[MacAttack]

Thanks Mark!

Mine has the older choke / AF cover like the Made in Mexico versions. It's actually a very clean saw, but the plastics are faded like it sat in a window (or outside) for a while. It's very funny because the saw says 35cc but it has a tiny sticker that says "displacement: 38cc".

I should have it together and hopefully running in the next week or so.