Stihl Bar Oiler Mechanical Question

Help Support ArboristSite:

Alaskan Stihl

Alaskan Stihl

ArboristSite Member
Joined
Jul 30, 2021
Messages
76
Location
Alaska
Stihl Oiler Question: I am in the process of putting together a “Stihl 031AV Basketcase Chainsaw”. So, I finally got all the parts in the mail and installed for the most part.

With a thorough Carburetor Rebuild, the Chainsaw fired right up and runs & idles like it should.

However…

I then noticed an excessive amount of Bar Oil being discharged onto the chain. Since I also have a second Stihl 031AV saw, I checked where the adjustment screw (aka “Control Bolt”) setting was on that saw for a point of reference (it was about midway between the “+” and the “-“).

The important thing here to pay attention to…is that when I turned the “Control Bolt” on the other saw (the good saw), it somehow has “Limiter Stops” for both directions (in other words, it will only go about 1/2 way turn in either direction before stopping). I am not sure how this operation works (what causes the control bolt to have limits…?)

PROBLEM: This saw (the one I am repairing) seems to have issues with the “Limiter Stops”…simply put…there are none. You can turn it to the “+” or the “-“ indefinitely it won’t stop.

QUESTION: Is this the reason it seems to be on “Full Open Oil Setting” (maybe because someone didn’t try to eyeball it into adjustment?) Since the Oil Pump itself appears to be working just fine (very well in fact), maybe the Control Bolt is still useable and I can eyeballit to dial it in? Or….is it toast and I should buy another oil pump?

Has anyone torn into these pumps?Any thoughts?

Thank you in advanced for any suggestions or advice!
 
hotshot

hotshot

ArboristSite Operative
Joined
Apr 11, 2009
Messages
2,879
Location
Midwest
On the late pumps, there’s a small pin through the control bolt shaft that often gets the tip sheared off by ham fisted operators. That tiny pin limits the stop.

It’s part #1117 647 9800 on the schematic. Don’t install the new pin with the bolt 180 degrees out, just compare it to your good pump there.

Should be an 031 Stihl service manual available on the “Beg For Manuals” sticky thread section here on AS, that takes you through the pump.

Not sure on the early pumps, have never rebuilt one.
 
Alaskan Stihl

Alaskan Stihl

ArboristSite Member
Joined
Jul 30, 2021
Messages
76
Location
Alaska
Stihl 031AV Update: I purchased a used Oil Pump and replaced the old one. Note: Once I had the old one removed, I notice the “Pin Stop” was sheared just as someone recommended (kinda wish I would have removed the pump first before assuming the pin would be too difficult to replace…).

Anyhow, now that a “Used” Oil Pump is installed (with new gasket), I started up the saw….only to discover it still spews out Bar Oil (just like before).

My first guess is going to have to be that there is a crack in the oil suction line.

Question: Does anyone have any other suggestions I could try checking into before I tear back into this thing?

thanks!
 
Top