Stihl 041AV not running

[BigCountry92]

I bought this saw off of marketplace. (His father in law passed away and he couldn't get it running) Oil is leaking out of the spark plug hole after I've emptied fuel and bar oil. I've tried new fuel with proper ratio. If I take the spark plug out I can pull the pull cord, if I put the spark plug in I can only pull the cord about 6 inches until it stonewalls me. I put new sparkplug in and it gets covered and dripping in oil. I just took it apart and put it back together and replaced carb gaskets but didn't see anything obvious. Any ideas? I'm at a loss at this point.

 

[BigCountry92]

I bought this saw off of marketplace. (His father in law passed away and he couldn't get it running) Oil is leaking out of the spark plug hole after I've emptied fuel and bar oil. I've tried new fuel with proper ratio. If I take the spark plug out I can pull the pull cord, if I put the spark plug in I can only pull the cord about 6 inches until it stonewalls me. I put new sparkplug in and it gets covered and dripping in oil. I just took it apart and put it back together and replaced carb gaskets but didn't see anything obvious. Any ideas? I'm at a loss at this point.

Additional info, I've taken the saw almost completely apart, the cylinder moves as it should, does not appear to have excessive carbon build up anywhere.

 

[BigCountry92]

I bought this saw off of marketplace. (His father in law passed away and he couldn't get it running) Oil is leaking out of the spark plug hole after I've emptied fuel and bar oil. I've tried new fuel with proper ratio. If I take the spark plug out I can pull the pull cord, if I put the spark plug in I can only pull the cord about 6 inches until it stonewalls me. I put new sparkplug in and it gets covered and dripping in oil. I just took it apart and put it back together and replaced carb gaskets but didn't see anything obvious. Any ideas? I'm at a loss at this point.

Also appears to have an intermittent weak spark.

 

[hunter72]

There is a o-ring or seal on the oil pump that you need to replace as I remember, to keep oil from migrating to the crankcase while sitting idle for a long time. I did one many years ago. You are getting hydro lock from the oil you cannot compress it.
Hope this helps.

 

[Brushwacker]

There is a o-ring or seal on the oil pump that you need to replace as I remember, to keep oil from migrating to the crankcase while sitting idle for a long time. I did one many years ago. You are getting hydro lock from the oil you cannot compress it.
Hope this helps.

I sold an 051 locked up years ago, later talked to the buyer, he said it was hydro locked.
I remember reading about the oil pump not sealing also.

 

[BigCountry92]

There is a o-ring or seal on the oil pump that you need to replace as I remember, to keep oil from migrating to the crankcase while sitting idle for a long time. I did one many years ago. You are getting hydro lock from the oil you cannot compress it.
Hope this helps.

Thank you! I

There is a o-ring or seal on the oil pump that you need to replace as I remember, to keep oil from migrating to the crankcase while sitting idle for a long time. I did one many years ago. You are getting hydro lock from the oil you cannot compress it.
Hope this helps.

Thank you! I looked into this exact problem on YouTube and the guy gave the proline part number for it! So, I have that ordered and I'll update as soon as I can. Any advice on getting the residual oil out after I replace that seal?

 

[BigCountry92]

Link to the oil pump seal in question

https://sawzillaparts.com/proline-o...stihl-041g-041av-041-farm-boss-1110-647-9000/

 

[hunter72]

As I remember I pulled the plug put the switch to off and flushed both the cylinder and crank case out with fuel mix. You have to turn the saw in many directions after you pour the mixture in the carb with the piston at TDC, to get the oil out of crank case. Then let it air out.
Hope this helps.

 

[stihltech]

Oh- you need an OLD tech that worked on a lot of these in the early eighties.
Remove the oil pump from the front of the saw by the bar. An M5 by 25 screw helps.
Disassemble the pump, keeping the parts in order. The oring will be on the pump body where the plunger goes in.

Take a good look at the plunger gear teeth. Check for wear. Clean all parts.
If using the old spring, give it a stretch. Don't have an exact measurement, but a good 3/8 longer was about right.

Reassemble. Oring into body, washer, and spring. Sometimes there was another washer between the plunger gear teeth and spring also. Have seen it both ways. Make sure the oring fits into the recess of the pump body. Lube with your favorite oil (not fussy).
Work the assembly back into the case. At most, small taps with a light hammer. When seated, reinstall c-clip. You will use a socket the fits the bore of the case to install the pump and seat the c-clip.
i would pull the plug and pull the cord MANY times to remove the oil from the cylinder. It will take a while. Never tried flushing, but worth a look. Until you get enough oil out to get the saw to start again, be prepared to have the starter handle ripped out of you hand.
Once started (a little priming will help) let it run until the fog stops. And it WILL fog!
Enjoy!

 

[stihltech]

As to the weak spark, check the switch and wiring. The plug wire where it exits between the rear shroud and fuel tank is a common place for wear and a short. You said AV and not AVE, so it should have points. When you get there, that is a whole nuthe lesson. But, these are very reliable saws with points.