SteveSr
Addicted to ArboristSite
Hello,
I recently got back one of our trail club saws and after maintaining it and sharpening the chain I went to go check it out in some wood. This is my normal procedure before getting the saw ready for storage or assignment to another volunteer.
This is a Stihl 025 that is setup with a 16" 3/8" LP bar and chain. Although the chain didn't smoke or lock up it definitely looked too dry for my liking (see photo). This was cutting green maple and red oak so no dry, dusty wood to soak up all of the oil. The oil consumption was about 1/2 tank of oil to tank of gas.
When I got home I decided to investigate further. With the B&C removed I ran the saw and didn't see any oil coming from the bar pad. Huh? I drained the tank and it was pretty clean. I removed the clutch and the pump was turning and the worm was intact. There was some indication of a small amount of bar oil behind the clutch collecting sawdust but nothing that I would consider excessive. The only thing left was the pump and pump connection. Unfortunately, the wrap handle has to be removed to get to it.
I pulled the wrap handle and the pump to tank connector was firmly attached and there was no sign of leakage or where the pump could suck air. I also pulled the oil line and pickup and found no issues.
I extracted the pump and the bar pad oil passage was clear. So now I am wondering if the pump is just worn out? The pump showed no signs of clogging. However, there is noticeable wobble/ play in the pump piston. There is also play in the vertical pump piston direction which may have an effect on the pump stroke. I attempted to measure the pump stroke and came up with 0.58mm which is in between the strokes of the two available pumps for this model. However, this may be inaccurate due to the vertical slop in the piston.
My current working theory is that the pump clearances are loose enough that the bar oil will flow back into the tank when the saw is shut off. The pump may also be sucking air around the piston shaft and the vertical slop in the piston may lead to reduced piston travel / oil flow.
Your thoughts?
Thanks,
Steve
I recently got back one of our trail club saws and after maintaining it and sharpening the chain I went to go check it out in some wood. This is my normal procedure before getting the saw ready for storage or assignment to another volunteer.
This is a Stihl 025 that is setup with a 16" 3/8" LP bar and chain. Although the chain didn't smoke or lock up it definitely looked too dry for my liking (see photo). This was cutting green maple and red oak so no dry, dusty wood to soak up all of the oil. The oil consumption was about 1/2 tank of oil to tank of gas.
When I got home I decided to investigate further. With the B&C removed I ran the saw and didn't see any oil coming from the bar pad. Huh? I drained the tank and it was pretty clean. I removed the clutch and the pump was turning and the worm was intact. There was some indication of a small amount of bar oil behind the clutch collecting sawdust but nothing that I would consider excessive. The only thing left was the pump and pump connection. Unfortunately, the wrap handle has to be removed to get to it.
I pulled the wrap handle and the pump to tank connector was firmly attached and there was no sign of leakage or where the pump could suck air. I also pulled the oil line and pickup and found no issues.
I extracted the pump and the bar pad oil passage was clear. So now I am wondering if the pump is just worn out? The pump showed no signs of clogging. However, there is noticeable wobble/ play in the pump piston. There is also play in the vertical pump piston direction which may have an effect on the pump stroke. I attempted to measure the pump stroke and came up with 0.58mm which is in between the strokes of the two available pumps for this model. However, this may be inaccurate due to the vertical slop in the piston.
My current working theory is that the pump clearances are loose enough that the bar oil will flow back into the tank when the saw is shut off. The pump may also be sucking air around the piston shaft and the vertical slop in the piston may lead to reduced piston travel / oil flow.
Your thoughts?
Thanks,
Steve
