McCulloch 10 Series Oiler

[heimannm]

Much of the information previously posted on the 10 Series oiler was lost with the site trouble last year so I thought I'd start a new thread. A few posts in I will add some details on the jig(s) I have been working on to facilitate drilling the oil tank to use the "three screw" automatic oil pump mounts.

All 10 Series saws have a manual oil pump, nothing more than a spring loaded piston that is operated by a button and push rod. To make the pump work there must be two check valves, one on the inlet side and one on the outlet side.

The check valve on the inlet side is nothing more than a small phenolic or aluminum disc that sits over the flange of the oil pick up line, and nest in a pocket in the manual pump. When the plunger is depressed, the oil presses the disc against the flange of the pick up line blocking the flow so the oil is pushed towards the bar. When the spring returns the piston to the rest position, the disc will lift and oil is drawn up the pick up tube into the manual pump.









One problem that I have run into with the inlet check valve is the different thickness of the flange on the pick up line. If the flange is thick and the gasket is thin, the valve is seated all the time and the pump will not be able to pick up any oil. I have overcome this by substituting a pick up line with the thin flange, or finding one of the thick gaskets. I have tried to double up the regular gaskets but that never seems to work for me.

Very early saws did not have the automatic oil pump, but all of the oil tanks were designed to accept the crankcase pulse operated automatic oil pump. In the absence of the automatic pump there was a check valve body (51, 52, 53, 54) that attached to the oil tank and contained a spring loaded ball for a check valve.



Stay tuned for more.

Mark

 

[MnSam]

Thank you Mark, I'll be gearing up to work on one of these soon.

 

[lmbrman]

thanks for this info, I have one sitting that I didn't know how to fix

-dave

 

[heimannm]

For all of the saws manufactured by McCulloch, the automatic oil pump on direct drive saws was operated by the pulse coming from the crankcase as the crankshaft rotates and the piston moves up an down. This creates alternating positive and negative pressure that drives a piston up and down in the automatic oil pump. The "piston" in the automatic pump is a thin metal rod attached to a phenolic disc, all held in place with an o-ring. 52 through 64 make up the automatic pump, 52-55 are the "piston", and the outlet check valve ball and spring are 62 and 63 held in place by the adjuster screw and cover, 58-60.



And in real life the parts look like this, valve body, adjuster block, felt breather/seal, spring, piston, and base gasket.



On the other end of the automatic pump is the check valve, adjuster screw, and cover. Some later model pumps did not have the cover and the check valve was not serviceable.



From the base of the automatic pump, the inlet is circled in green, the outlet red. You can test the operation of the automatic pump by putting a little light oil in the inlet side and pumping the piston manually, eventually you will see oil pumping up and out of the outlet. This is a good way to verify that the piston is moving freely and that the check valve is working.

It is also possible to test the operation of the check valve by pressurizing the outlet side as shown here.





More to come, I promise.

Mark

 

[heimannm]

Older models had the automatic pump held in place with three screws, later models used a single screw. The three screw system provides a very positive seal between the automatic pump and the base, but requires removing the fuel tank to gain access to the mounting screws if you have to remove the automatic pump. The single screw did not prove to adequately secure the automatic pump and provide a good seal, if you have a saw that smokes heavily there is a good chance some bar oil is getting past the gasket at the base of the automatic pump, into the crankcase and eventually into the combustion chamber.

To overcome the leaking / burning bar oil, McCulloch tried a couple of fixes. One was a spring clip on top of the automatic oil pump that helped press the pump body to the gasket. The other was a piece of spring steel at the back side of automatic pump that wedged the pump body against the gasket. The pump body on the left does not have a serviceable check valve, the pump body on the right has the cover under the clip making the check valve accessible to disassemble and inspect, clean, or replace as needed.



The spring clip was fixed to the top of the automatic oil pump body by the volume adjusting screw. I have found this is not a sure fix to the burning bar oil problem.



It is quite difficult to see the wedge device with the automatic pump in the saw but the illustration below should help. If you ever happen upon a supply of the kits 215246, buy them all and give me one or two for the efforts here. The kit included a new gasket and the wedge type clip, plus a couple of brass eyelets that install in the automatic pump body to prevent the clip from digging into the plastic pump body.



Mark

 

[heimannm]

Here are the parts included in 215246





Some clever guy, probably one with a laser could make some spare wedge clips for all of us.





Mark

 

[machinisttx]

Good to see this one back.

 

[heimannm]

McCulloch made a lot of changes as they went along. Early oil tanks had the three screw mounting system for the automatic pump body or check valve body.



Later tanks had the single screw mounting system, but the provision was there for the three screw system. Converting these to three screw mounts is very easy as the hole locations were clearly marked.



The latest models were intended for the single screw only and there was no easy way to locate the three holes if you wanted to change the mounting system.



The automatic oil pump bodies were also different, notice the three screw model on the left, and the single screw model on the right. Note that the single screw model has all of the other holes provided. I don't think the holes under the eyelet are tapped but that could be remedied easily enough.



Finally, some of the early attempts at the single screw mount pumps included a dog point set screw to help locate the automatic pump body in the tank.



Mark

 

[heimannm]

I wanted to come up with a jig or fixture that would allow me to locate the three holes so I could use the three hole mount system on saws and automatic pumps that were originally single screw. My first thought/attempt was to install some steel spacers to a three hole tank and pour epoxy (JB Weld) around them. I tried it, but discovered that with the difference in the tanks that was not going to work.





My next attempt was an 1/8 thick steel plate with holes drilled to line up with the mounting holes and insert the spacers in them to act as drill bushings.
The trouble for me was trying to measure and layout holes that were located on different planes in three dimensions. I finally broke down and slotted the single hole to lay it out and mark the location for the third (single) hole.



From that, I could more accurately identify the location of the holes and came up with a good template.



I still had to locate one last hole to line up with the single screw mount, this way you can use the location of the existing single screw hole to properly orient the jig on the tanks with no other provision for the three holes. Fortunately I had one tank with the three holes located (not drilled) and the single hole drilled and tapped. From there it was a relatively simple matter to attach the jig to the oil tank and drill the holes as needed.



As you can see here, I was able to drill the hole more precisely than whoever simply punched out the knock outs on the CP55 tank.




Mark

 

[Steve NW WI]

Mark, I'd need some more dimensions, or possibly a sample to work with, but that keeper clip looks pretty simple to make. I assume spring steel?

Send me a conversation, and I'll see what I can do for you.

 

[heimannm]

You may have noticed that the late model saws did not have the hole locations cast in, and in fact the design of the tank changed so the jig cannot mount directly to the tank due to the narrow channels on either side. I overcame this by using one more spacer under the jig and fastening the jig in place with the single screw mounting tapped hole. I forgot to take a photo of that, but will try to get one up so make it clear. Because the channels are so narrow, it was necessary to use a fillister head screw or socket head cap screw to mount the pump. Here you can see the three hole mount pump installed in the oil tank from and SP80/81 type saw.







That's it for now, I will follow up with some more photos and try to get a more detailed dimension drawing put together.

Mark

 

[Eccentric]

Thanks for all the hard work Mark. I hope we can get Mike on board making some reproductions of that jig for us.

 

[heimannm]

I had a few minutes before lunch today so I put one of the jigs on the SP81 tank using a spacer so you can get the idea. Since the jig won't fit properly in the channels, it is necessary to position the jig a bit above the oil tank. I used a longer spacer than necessary here to make it more obvious. I dropped a drill bit through the single hole just to give you an idea how it looks.



You may notice this is a different jig than the one shown in the earlier photos. When I was looking through my supplies I found a piece of 1-1/2 x 1/2" hot rolled bar and thought it might make it easier to keep the drill bushings (spacers) square to the jig if I counterbored the body of the jig. Since a have a new mill/drill and some tooling I thought why not?



After all of the work trying to layout the holes, it dawned on me yesterday that I have any number of perfect templates already on hand. For some reason I just couldn't see this when I was looking at the oil tank with the mounting holes at a angle to the top of the tank...guess I am getting old and the brain is becoming a bit brittle.



My only welding option here are stick (not practical on a small piece like this) or my little flux core wire welder. The first few are together but they are not very pretty.
You can also see that to fit the spacer where it needs to be when drilling the late model tanks I had to machine the front drill bushing (spacer) to keep the hole as close together as they need to be.



Anyone else out there with tips or tricks for the 10 Series oilers, please chime in.

Mark

 

[rwoods]

I had a few minutes before lunch today so I put one of the jigs on the SP81 tank using a spacer so you can get the idea. Since the jig won't fit properly in the channels, it is necessary to position the jig a bit above the oil tank. I used a longer spacer than necessary here to make it more obvious. I dropped a drill bit through the single hole just to give you an idea how it looks.

View attachment 326153

Anyone else out there with tips or tricks for the 10 Series oilers, please chime in.

Mark

Mark, I decided to modify my second generation design after looking at your photos and playing with it a little in my mind. I had intended to make a jig that attaches in the oil tank and centers off the two oil passages (that is why the jig has the two passage holes drilled), but after realizing that it would be a good 2 1/2 inches tall and having nothing but hand tools to cut it, I decide to try the single pedestal design. As you know there are no "on plane" flat surfaces on the top of the 82cc crankcase other than the main oiler screw boss. On my earlier wood jig I bridged across to the bearing side of the case, but found that it was too easy to tweak the jig when tightening it down which would throw off the angles. The jig touches nothing other than the pedestal. You can see I tinkered with my spacers to get it as close to the drilling surface as possible without touching the crankcase with the back of the jig. It dawned on me that I was spending too much time worrying about centering the jig mechanically (I wanted to use the oil passage hole but it is drilled on a different angle than the mounting screws). Since things are so tight on the 82cc case , I have come to conclude that eye-balling it is the best approach for me. Two starter cover screws are ideal to sight the jig in, prior to your final tightening. With a thicker jig than mine, you might could drill a small centering/stabilizing hole straight from the clutch side upper crankcase screw hole.

For those who have not done this on a 82cc MAC, you can see in Mark's picture that the allen head scrubs the crankcase wall - there are just two tiny slots to fit the screws between - whatever you gain on one side you take away on the other - if you mess up just remember JB Weld can be your friend - that's how I fixed my freehand mounts after trashing my first jig - it is the grey stuff you see in my pictures - this was a freehand drill job that worked so I mounted the jig on it to see if the jig lined things up properly.

I note that Mark is drilling three holes. I decided to stick with just the back two and use the original front screw.

Ron

 

[heimannm]

Thanks Ron - how long would it have taken me on my own to realize I only needed to add the two rear holes to fix the heavy smokers? Of course if you are going to use a really oil automatic oil pump you will need all three holes as you can see in the side by side pumps in post #8.

Mark

 

[rwoods]

Mark, I don't have any of the good old metal oilers. With the three screw conversion, can't we ditch the plastic wedge and just use the flat gaskets? Ron

 

[heimannm]

I'm not sure I understand "the plastic wedge", but I think you are correct in that the ordinary thin gaskets should work with the three screw conversion since the pump will now be firmly held in place at both ends. The thick hard rubber "seal" as they called the gasket on the later saws was necessary to try and make the single screw holding system work.

Mark

 

[rwoods]

I assume that the theory of the wedge was the thick side would make up for the lack of even tension. To this untrained eye, it appears to be a pretty high tech device with individual sealing rings/lips on both sides for each passage. IIRC the last one I bought came in a package marked made in Japan. Too bad they don't always work. Ron

 

[naturelover]

A dumb question, but does the oil filter just pull off the oil pickup tube to remove the pickup tube from the case?


Sent from my iPhone 5 using Tapatalk

 

[heimannm]

No dumb questions. The oil pickup tube is molded like many Mac fuel and oil lines. To remove and replace it you have to work the small flange at the top end through the hole in the top of the oil tank, it can be a challange.

Mark