MS251 help

[stretch5881]

I have 2 ms251's on the bench. The owner put new Stihl bars and chains on them and they quit oiling. I had found the oil lines and pump were shot in both of them. Replaced with oem. He has been using them for storm cleanup and brought them back today because of oiling issues. Both saws outfeed oil line look like they blew out.
Any thoughts?

 

[Wood Doctor]

I have never seen this occur on a Stihl 025, 250 or even a 251. It has to be rare to say the least. Gasp!

 

[Chainsaw-57]

Does the owner clean saws with compressed air?

Maybe blowing back into oil passage?

HOS

 

[stretch5881]

Does the owner clean saws with compressed air?

Maybe blowing back into oil passage?

HOS

He does a general blow off when he finishes for the day. He's been doing that for 40 years.
The 1st saw failed after 1/2 hour of limbing a tree on a roof. He noticed the chain getting hot and oil dripping from under the saw.
The 2nd saw pump line failed before it even got into wood.
I checked the ipl to see if I missed something, but no, it's pretty simple.

 

[cus_deluxe]

100% sure clutch drum was engaged in oiler drive correctly? if not i could see it pushing that tang down and clipping that oil hose on the way around.

 

[stretch5881]

100% sure clutch drum was engaged in oiler drive correctly? if not i could see it pushing that tang down and clipping that oil hose on the way around.

Yup, I double check that the drive is in the notch every time.

 

[stretch5881]

I looked at them very close and don't see any sign of them being clipped by anything. ?????

 

[cus_deluxe]

interesting.

 

[stretch5881]

Today I received "not made in china" oil lines from Proline. They fit good and are firm. The oem lines are mushy. I have nothing to lose by trying.
They may be Stihl's throw away saws but they are his go to saws in the bucket.

 

[Henry E]

Wonder if the lines were so old they were rotting and gave out once pressurized.

 

[stretch5881]

Wonder if the lines were so old they were rotting and gave out once pressurized.

I don't know, but they were swelled up and mushy. He doesn't add anything funky to his bar oil either.

 

[stretch5881]

Mystery solved. He let slip that he was using used hydraulic oil from his boom truck. This is the third set of hoses for that saw in 2 months. The hose on the bottom is only a month old. It swelled up and the oil pump drive clipped it.
His lube education has cost him quite a bit.