Hot Stihl 251

[HarleyT]

So all you would need is the cover and 1 bar stud. Here is an old MS170 cover on it....

 

[Stoneguy]

Me again. I have not as yet added a second stud with a different cover. I did do a good cleaning and sharpening of my bar and chain, made sure the oil holes were not blocked, and reassembled. Started it and ran a little, checking that oil was flowing properly. It does not appear to be. I don't get a visible spray when run over clean wood, but I do get a lot of oil sprayed all around inside the cover. Looking closely (not an easy task with these old eyes), the chain was a little wet, but nowhere near what I would expect based on the mess all around the clutch and sprocket. Is this the nature of this saw? The rubber grommet looks OK, oriented correctly. Baffled. It seems as if maybe oil is traveling out on the sides of the grommet. I that easy to replace?

 

[HarleyT]

Here is a pic of the crankcase with the lines still in place.

 

[Stoneguy]

The oil pump sits in there behind the clutch, sucks oil in from the lower line, and dribbles it out the top line/grommet? Looks like a likely spot for a leak. I can't see depth here, but I guess there a rise of that upper line, which is hidden be behind the rear clutch cover piece, still in place here:

 

[HarleyT]

Why don't you just run the saw like that and watch where the oil is flowing from? With no bar/chain as in your pic?

 

[Stoneguy]

Because that never occurred to me. Another Duh moment for me.

 

[Franny K]

. Started it and ran a little, checking that oil was flowing properly. It does not appear to be. I don't get a visible spray when run over clean wood, but I do get a lot of oil sprayed all around inside the cover. Looking closely (not an easy task with these old eyes), the chain was a little wet, but nowhere near what I would expect based on the mess all around the clutch and sprocket. Is this the nature of this saw?

I think what you describe is normal. At times I have had a hard time getting oil to spray off the end but have a mess at the sprocket. I have decided that due to the fact the drive sprocket is a tighter radius than the nose sprocket oil is more likely to come off there. It isn't only the model saw you have. Sometimes the oil coming off the bar at the end will only make wetness on wood or whatever is just about pointing straight down not like the picture in the manual. There should in my opinion be some cohesion range where the oil could stay stuck going around the nose but not going around drive. It may be something to worry about but do not worry too much unless it is clear the oil is leaking out at the bar contact area which is not a spray.

 

[Stoneguy]

Thanks FrannyK, I had hoped to hear a reply like yours. I'll fire mine up without the cover & bar after a bit to look for errant drops as HarleyT suggested.