Stihl 009, 009L, 010, 011, 012 bar oil feed fault

[StihlSolo]

For those that still use these little saws, ever wonder why the bar oil goes everywhere under the side cover? Guessing that I'm not the first to notice this, but the bar oil feed slot on the crackcase side does not match the oil pickup hole in Stihl bars.

Technical stuff: distance between crankcase bar mount stud centerline to centerline of oil feed slot is about 12.5 mm, see first photo. For most Stihl bars, distance between bar mount slot centerline and centerline of bar oil pickup hole is about 20mm, see second photo. Big mismatch. But it happens that the adjuster hole in Stihl bars does overlap the crankcase oil slot. That hole also opens into the bar guide.



So with the mismatch, oil from the saw is pumped through the topside adjuster hole in the bar, and some then goes directly into the bar through the opening between that hole and the bar guide. The rest goes through the hole into a slotted recess in the side cover. Think thats where the mess starts, leaking from the boss.

As far as I know, a quick down & dirty fix is to slot the bar down from the pickup hole. Doesn't fix the oil-spray-everywhere problem though. For that, going to try filling that recess in the side cover, then smoothing the whole side cover boss.

 

[Mad Professor]

For those that still use these little saws, ever wonder why the bar oil goes everywhere under the side cover? Guessing that I'm not the first to notice this, but the bar oil feed slot on the crackcase side does not match the oil pickup hole in Stihl bars.

Technical stuff: distance between crankcase bar mount stud centerline to centerline of oil feed slot is about 12.5 mm, see first photo. For most Stihl bars, distance between bar mount slot centerline and centerline of bar oil pickup hole is about 20mm, see second photo. Big mismatch. But it happens that the adjuster hole in Stihl bars does overlap the crankcase oil slot.
View attachment 743814
View attachment 743817

So with the mismatch, oil from the saw is pumped through the topside adjuster hole in the bar and sprays everywhere inside the side cover, but not directly into the bar. Only way oil gets into the bar is roundabout by scavenging up the oil that just happens to dribble in from the spray.

Was this an intentional f**k-up?

As far as I know, a quick down & dirty fix is to slot the bar down from the pickup hole. Doesn't fix the oil-spray-everywhere problem though.

In the first picture you are measuring from the top bar stud to the oil hole (shorter).

I the second from the slot bar center to the oil hole (longer).

Measure the top bar stud hole center to oiler hole on bar (shorter). Or from adjuster stud on case to oil outlet (longer). I think you'll find the shorters match the longers.

Those saws have a rather unique oiler. If they are pissing oil check the gasket/cover on the oil pump, the cover screws tight, and old style cover the cover cap. There is also a vent hole right below oil outlet on case that is fitted with a split pin, check that too.

 

[awful knawful]

I have a 009 I just fixed up.

Fired only to test. Oil mess for sure.

Fix?

 

[StihlSolo]

For part of a fix, going to try filling that side cover recess (w/ JB Weld Plastic Bonder), smooth the side cover boss, tighten the cover down and see if that cuts down on the spray.

On a test bar, kerfed in a slot from the adjuster hole to the oil feed hole. If more of the output gets to the bar guide, then maybe that'll cut down on the spray. See how all this works tomorrow.

Like the carburetor diaphragm, the 1120 oil pump is run by the crankcase's premix-vapor pressure changes as the piston moves (there's a tunnel between the crankcase and the oil pump boss). Restricting where the output goes should not badly affect the oil pump.

Yeah, the cotter pin filled hole is the tank vent. The vent opens into an air pocket at the top of the oil tank. That air pocket gets filled with oil if the saw is held clutch side down, hung by its tail (w/ bar hanging down) or put on its tail for too long. Then the vent leaks oil, but not as much as the spray. If someone messes up the cotter pin (had a customer try to pull one out) then the tank can leak more.

 

[awful knawful]

Any pics?

 

[StihlSolo]

Filling the slot and smoothing/plane-ing the boss made all the oil pump output go to the chain guide. Kerfing bar just made that flow easier. Chain is so wet that you can see oil globs flying off the chain along top and bottom runs, and again flooding inside the side cover. I have 3 of these 009L's presently, one oils OK, two oil way more. Going to rebuild pumps & replace compression springs, which is what I thought I had to do in the first place but was trying to avoid that hassle. Pictures for the slot, unfilled and filled, and oil coating side cover from the flood follow.


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[awful knawful]

Thanks

 

[davidwyby]

Does anyone know have a way to get ahold of @StihlSolo?