STIHL 1110 Series (040, 041, 041 Farm Boss, 041AV, 041 Super) 1968 - 1982

[D'Animal]

I have had several requests through PM's on a few of the older saws. I will continue to add the detail on them as the requests come in.

This covers the oil pump repair on the STIHL 040, 041, 041 Farm Boss, 041 AV, 041 AVE, 041 Super.

 

[D'Animal]

Remove the side cover and the bar and chain.

Remove the spark plug.

This is the correct Piston Stop to use.

Screw it into the spark plug hole. No need to tighten it down just lightly thread it all the way in until it seated all the way up the thread.

 

[D'Animal]

The nut comes off to the right, clockwise.

Some older ones will require a 13mm wrench, some middle aged one use a 19mm wrench, some newer ones will not have the nut. The center of the clutch is the nut.

 

[D'Animal]

The Clutch assy come off to the right.

This is the correct spanner wrench for removing a 3 shoe clutch.

 

[D'Animal]

Behind the clutch is a large washer.

You then remove the sprocket drum.

Some versions will have a small spacer washer on the crankshaft and then the bearing. Not all version have this spacer.

You then have a washer with a pin through it. Inspect the pin and make sure it is not sheared or worn out. If the pin is sheared, the oiler will not work.

 

[D'Animal]

Remove the oiler drive gear. I use needle nose pliers and wiggle it or unscrew it.

Make sure the teeth are not worn off. Make sure the oil seal inside the gear is in good shape. If you use your chainsaw to field dress and quarter large game, you will probably have hair wrapped in there.

Look inside the oil seal at the driven gear adn make sure the teeth are not worn off.

 

[D'Animal]

There are a few reason you would need to remove the actual oil pump.

If your 1110 series:

leaks oil out the front of the saw behind the bumper spikes.

Does not oil and the drive pin is good.

The crankcase/cylinder fill with bar oil.

Start by removing the bumper spikes. Should require an 8mm or 5/16 wrench.

 

[D'Animal]

Here is the end of the oil pump.

Remove the "C" Clip.

 

[D'Animal]

To remove the actual pump, remove one of your starter screws and thread it into the top hole of the pump.


Use needle nose pliers and gently pry the pump out.

 

[D'Animal]

Here is the oil pump.

The long skinny part is the drive piston.

The sequence is washer, spring, washer, spring on the drive piston.

Make sure the gear is not stripped.

 

[D'Animal]

If your 041 has a problem filling the crankcase with oil and the motor hydrolocks, this O ring in the end of the oil pump housing is cut or leaking.

 

[Dan_J-spec_fj62]

Dan!

Awesome! Thank you!. I'll tear into my saw and let you know what I find.

Thank you,

Dan

 

[D'Animal]

If your saw is leaking from the front. This rubber boot on oil pump is bad.

 

[D'Animal]

When you assemble averything, make sure it is lubed up the bar and chain oil so it slides together easy. You do not want to cut the O ring or the rubber boot.

 

[D'Animal]

Apply some grease to the inner seal of the oiler gear as well as the outer seal in the crankcase and slide the gear back into place.

Install the plate with the drive plate back onto the crankshaft.

Grease the sprocket bearing. Install the spacer washer, if equiped.

 

[D'Animal]

Install the drive sprocket. Align the hole in the gear part of the sprockt with the drive pin.

Slide the washer on after the drive sprocket.

The clutch only goes on one way!

One side of the spider (center) has a recessed part of the threaded center.

The recessed side goes towards the engine.

 

[D'Animal]

Spin the clutch on. Install the washer and then the nut. Tighten the nut down.

Make sure your inner and outer guide plates are not worn off.

Remove the piston stop, install the spark plug, clean the air filter. etc.

 

[ghenry]

if the oil pump o ring is replaced and still chain oil is getting into the crankcase, where else is it possibly coming from ?

 

[D'Animal]

Did you replace the "O" ring and the rubber sleeve?

Sent from my iPhone using IH8MUD

 

[ghenry]

no, just the o ring...rubber sleeve is soft and looks fine..it only stops it leaking to outside of saw I think...I don't see how that sleeve could allow oil into crankcase