McCulloch3.4 Eager Beaver or Timber Bear - No Oil To Chain

etbrown4

No doubt the passage from the oil tank is plugged.
I've put a lot of air pressure on the tank but can't get any oil to exit.

I am sure the oil is supposed to exit right near the chain or sprocket, but I have not been able to identify the exact spot for further attention.

If anybody has a pic of the exit point for the oil that would be a big help!

These saws are well known for plugged oiler lines, so any tips would be appreciated!

ScottyAFoster

Take the pump off the saw then try blowing the line out.

etbrown4

Took the pump off the saw, cleaned it, tested it for good pumping action, put it back on saw, and still no oil!

Once again, the outlet point for the oil seems to be obscured by a very large but thin, cover plate which goes behind the clutch and behind the area where the two studs hold the bar. So you can see the exit point, but there is zero oil that I can find anywhere, even though the oil tank is full.

Does anyone know if the oil tank is removable on this saw, or have other ideas?

ScottyAFoster

Get your self a fine wire and poke around the oiler outlet tube.
Get some picts up of her.

etbrown4

Well it's all apart, torn down and oil tank removed and I really had to go that way. The suction tube in the oil tank was stiff or brittle. I had just gently probed in the tank, and the next second the tube and the strainer fell to the bottom. The filler hole is so small that once this happens, you HAVE NO CHOICE but to tear the thing apart! The knuckleheads at McCulloch designed it so that the neither the tube nor the strainer is user serviceable! Pitiful design. As it turns out the strainer was clean. Al they had to do was to give you a cap large enough for your fingers, and I could have saved a few hours.

I've run a wire through the inlet port and can see that wire where it enters just beneath the pump. I ran another wire from the outlet by the chain back to the pump and can see that wire directly beneath the pump. I have completely disassembled and cleaned every part of the pump.

My only remaining thought is that one or both of the diaphragms may need replacing, though they look fine. I'd be happy to put on a new pump if I can find one.

Isn't it amazing how much time you can spend on such a small problem? I'd lay most of the blame on McCulloch, because the design is just so incredibly poor. They make it so hard to access these parts and so hard to troubleshoot. Possibly that might be part of why they are no longer around!

No telling if I can get these parts. We shall see. Some guy does have them on ebay for $35! Too steep for this old saw, so I'll keep looking.

Besides an 'old style' Eager Beaver, and an 'old style' Timber Bear, it seems that they may have called this saw a Pro Mac with displacements of up to 3.7 ci.

Thanks for the great tips!!!

ScottyAFoster

You need to replace all the hoses first. Make the vacum port is sealed tight.The pickup hose being bad may be your whole issue.

etbrown4

I've got the tank off and all ports exposed.

Using a new suction hose it will draw oil nicely from a container. It's the only hose there is on this model 600 Mac saw.

Since I've run wires completely through the inlet and outlet ports, I'm running out of things to try.

The inside of the pump is as cleans a a hound's tooth!

When I push the oiler button several times you can feel it building a back pressure, but no oil comes out anywhere.

It could be a diaphragm or maybe a check valve in the little pump. It's hard to say.

The likely next step may be a diaphragm or a pump.

ScottyAFoster

Check to see if there is vacum port under the oil pump. Put all new hose on the saw and reassemble the saw and try it. The oil pump works off of the crank case vacum.

etbrown4

I think this oiler is completely manual.

There are so many ports on the bottom of this pump you would not believe it.

While it's possible, I'd be real surprised if this runs off of engine vacuum.

With the suction strainer dropped into a container of oil, it draws the oil well......

It's as if the discharge side is blocked, but then I've run a piece of wire all the way through that side too.

In studying the pump it seems that there are possibly 2 check valves on it. With those and so many ports, it's pretty hard to know what's happening or where else to look.

ScottyAFoster

Do not fear. I can tell you it has both a manual and a automatic oiler. Make sure the pump has tight seal to the saw,that is were the saw makes the vacum side of the pump work. Check the pump out around all seams for air leaks. You can test the vacum side with a turkey baster,do not ask me how I know

etbrown4

are you saying that with the MAC 610 with the motor off, if you push the oiler button that you are not supposed to see oil exit the port beside the chain?

I have this saw in so many pieces that the last thing I'd want to do is reassemble it without knowing for sure that oil is flowing at least manually!!!!!

ScottyAFoster

The manual oiler is a separate circuit from the auto . I think you did fix the problem by replacing all the old oiler hoses.

etbrown4

I've got another guy with a Mac 610 who is going to let me know tomorrow if his puts out oil by pushing the button without the motor running.

Will let you know.