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Milling 3120 XP leaks chain oil through muffler, any hints.

buzz sawyer

buzz sawyer

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Yes, I applied seven pounds of pressure with cap off for three minutes using a mityvac and needle remained steady. Could it be a defective oiler excessively lubricating the crankshaft pin hole?
No way bar oil is getting inside the muffler through the oiler. If it's oiling excessively, it could be spraying up onto the muffler, but tha even seems far fetched. What pinhole are you talking about?
 
Anniwoodlator

Anniwoodlator

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There's a little hole on the side of the crankshaft where the clutch meets the oiler. That hole creates a vacuum which brings bar oil all the way into the crankshaft to lubricate the bearings. Maybe that bar oil is making it's way up into the piston as well.
 

J D

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I had a 390XP that I knew had a leak between the tank & crankcase. Took me 3 goes to find it... didn't show up under pressure/vac... didn't make bubbles underwater... only became apparent when everything was hot. Got loctite to whick into it when it was hot & under vacuum & it appears to have fixed it but I haven't put the saw back to work yet.
 
Anniwoodlator

Anniwoodlator

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I had a 390XP that I knew had a leak between the tank & crankcase. Took me 3 goes to find it... didn't show up under pressure/vac... didn't make bubbles underwater... only became apparent when everything was hot. Got loctite to whick into it when it was hot & under vacuum & it appears to have fixed it but I haven't put the saw back to work yet.


My 3120 xp doesn't get hot but shots out bar oil from the muffler. Thought of that too and replaced crankcase gasket for a new thicker one. I believe the crankshaft lube hole one way valve is broken and is suctioning air and bar oil into the engine.
 
Anniwoodlator

Anniwoodlator

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Its only there to lube the clutch bearing, you need to plug it to do a vac/pressure test. For your bar oil issue you most likely need to replace your crankcase gasket.
I did change the gasket and it's sealing, used my thumb to plug it and pressure/vac tested it for three minutes and gauge needle remained steady, but still there's oil coming out of the muffler. Oil/gas mix ratio is fine too. How would you plug it?
 
buzz sawyer

buzz sawyer

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I thought the crank bearings were lubed with the oil in the fuel. If there is a hole in the crank into the crankcase, how did it not leak during your pres/vac test? OK, you caught one with your trolling BS. Glad the ignore button still works.
I apologize for this earlier post and have asked for it to be deleted and sent an apology via PM. I was not myself when it was made.
 
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