Stihl MS261 leaking bar oil from oil adjustment screw

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Thanks for the response buddy. I should have added that this saw is only 8 months old, so I assume it's under warranty still? Maybe I could take it to a shop?
It is HIGHLY unlikely that the pump is bad or even leaking. Pull the bar, chain, and clutch drum off and clean everything up. You can even pull the metal inner guide plate off to see if it is leaking out of the tank vent.

Keep in mind that there are NO seals inside the pump, just manufacturing clearances. So you will get a "leak" as temperature shifts pressurize the tank and force oil out the bar hole. Heavier oil leaks less.
 
It is HIGHLY unlikely that the pump is bad or even leaking. Pull the bar, chain, and clutch drum off and clean everything up. You can even pull the metal inner guide plate off to see if it is leaking out of the tank vent.

Keep in mind that there are NO seals inside the pump, just manufacturing clearances. So you will get a "leak" as temperature shifts pressurize the tank and force oil out the bar hole. Heavier oil leaks less.
There are 2 O-rings in the adjustment assembly.
But, that young a saw shouldn’t leak from the pump at all.
 
OK- diagnosis time. ( yep-here I come again).
clean it all up and remove the clutch and the covers. Fill the oil tank and let it sit on some papers (as stated before).
I am finding (using my pressure and vacuum pump) that applying a few pumps of pressure to the oil tank vent will speed up the process. Keep a good watch on it every few minute or so. The leak will show.
Have not seen it come out the bottom of the pump at the adjuster before, but never say never!
The pump to pickup tube is pretty common. The oil cap is number 1. Secret- keep it clean.
If an oil pump is in a certain position, oil can pass through. Just had one in the shop. Had a leak, turned the worm 1 turn, no more leak. Would not guarantee a new pump would cure it.
Sometimes the pump screws will enter the oil tank. You may find sealant on the original screws. Also make sure they are tight.
That about does it under the clutch. Oil tank gasket and vent would be outside.
Good luck. Store it empty Problem solved.
 
Yes saws leak bar oil, but normally from the oiling channels near the bar, not the pump nor the adjustment screws. This seems odd and you could end up with oil in the clutch which would not be great.

As per my previous post I’d still investigate this.
 
OK- diagnosis time. ( yep-here I come again).
clean it all up and remove the clutch and the covers. Fill the oil tank and let it sit on some papers (as stated before).
I am finding (using my pressure and vacuum pump) that applying a few pumps of pressure to the oil tank vent will speed up the process. Keep a good watch on it every few minute or so. The leak will show.
Have not seen it come out the bottom of the pump at the adjuster before, but never say never!
The pump to pickup tube is pretty common. The oil cap is number 1. Secret- keep it clean.
If an oil pump is in a certain position, oil can pass through. Just had one in the shop. Had a leak, turned the worm 1 turn, no more leak. Would not guarantee a new pump would cure it.
Sometimes the pump screws will enter the oil tank. You may find sealant on the original screws. Also make sure they are tight.
That about does it under the clutch. Oil tank gasket and vent would be outside.
Good luck. Store it empty Problem solved.
Pump screws in the oil tank?
turned the worm one turn?
Please explain
 
Yup, dealers here suck... have tried both within an hour and on my last saw they would charge me and just say they couldn't figure out the issue. Very annoying.

Out of curiosity do you know, is all work under warranty free 100%? Or is it one of those things where the parts are free but you pay labor? Because if that's the case I rather just buy the parts out of pocket and work on it myself!

I also have this faint memory of Pro saws only having a year warranty possibly? Do you know about this? Anywhere I can check?
thankfully our Stihl/JD Dealer is pretty square. doesn't recommend or charge for anything more than you need. i had a farm boss that wouldn't start. he checked it and said it would be cheaper to buy a new saw....lol. gave me $50 bucks off the new saw because he couldn't fix the old one within reason.
 
If an oil pump is in a certain position, oil can pass through. Just had one in the shop. Had a leak, turned the worm 1 turn, no more leak.
I kind of suspected that this was true. How did you prove it? Pressurize the tank?

Sometimes the pump screws will enter the oil tank. You may find sealant on the original screws. Also make sure they are tight.
How would this happen? Most pumps are near the crankcase and not the oil tank?
 
Not all screws are in the crankcase. Depends on the saw.
Turn the sprocket about a turn. Does not work on a non pro 026 or any saw where the worm drive is attached to the crankshaft and not driven by the sprocket .
A little pressure, by a hand pomp, in the tank vent just speeds up the process.
 
Wow, I missed a lot of convo on this post haha! Thank you all for your input. I thoroughly cleaned the underbody of the saw and also removed the sprocket to get back there and clean additional oil. Not sure if this had anything to do with it, but I turned the adjustment screw back and forth a few times to ensure something wasn't wicking oil through the o-rings or something like that. I also brought the saw into my garage which fluctuates from 40-60F as opposed to 25-50F outside when I store this in my outdoor shed.

2 days later and minimal to no leakage on cardboard, and apparently none from the adjustment screw. I hear it all the time but I guess I needed reminded: Stihls just leak!

Thanks all
 
Wow, I missed a lot of convo on this post haha! Thank you all for your input. I thoroughly cleaned the underbody of the saw and also removed the sprocket to get back there and clean additional oil. Not sure if this had anything to do with it, but I turned the adjustment screw back and forth a few times to ensure something wasn't wicking oil through the o-rings or something like that. I also brought the saw into my garage which fluctuates from 40-60F as opposed to 25-50F outside when I store this in my outdoor shed.

2 days later and minimal to no leakage on cardboard, and apparently none from the adjustment screw. I hear it all the time but I guess I needed reminded: Stihls just leak!

Thanks all
Glad you got it sorted. Its amazing the benefits cleaning can do. If the leak returns, try removing the oil pump, cleaning that, the washers leading to the inflow and outflow and squirt WD40 down the inflow and outflow pipes..
 

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