# signs of a bad crank case seal?



## TreeSurfer (Sep 26, 2012)

what are the signs of a bad crank case seal? how will the saw sound or run?


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## angelo c (Sep 26, 2012)

the biggest sign is that it leaks air when you pressure test it.... hehe !!!!
Don't forget some soapy leak finder and spin the crank a few times while the tester is on for the full test.


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## Dan Forsh (Sep 26, 2012)

Really bad it will want to rev to infinity (until it seizes), if it's been progressive and you have been retuning the carb you might have masked the problem to some extent. If it will idle try holding it in different positions and see if this effects the idle.


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## SilverKing (Sep 26, 2012)

A saw that wont idle down like it should.Once it does idle down,it dies .I have always bought A LOT of used saws.Since ethanol came into play,every saw I buy seems to have bad crank seals.Just remember a saw sucking air through the crank seals is running lean,and will toast the piston and cylinder.Which is also common with every saw I buy anymore


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## nmurph (Sep 26, 2012)

There's no such thing as a crank case seal.


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## Dan Forsh (Sep 26, 2012)

nmurph said:


> There's no such thing as a crank case seal.



No, but we know what he means.


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## lone wolf (Sep 26, 2012)




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## greg409 (Sep 26, 2012)

treesurfer, all of the above, generally first signs are erratic idle.

However, bad intake gaskets will cause similiar symptoms, seals can cause the idle to change with orientation of the saw, as mentioned above.

luck,greg


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## tolman_paul (Sep 26, 2012)

nmurph said:


> There's no such thing as a crank case seal.



If your crankcase gasket, cylinder gasket or crank seals fail, then your crank case is no longer sealed.

There may not be a part called a crankcase seal, but the crankcase must be sealed to allow the saw to run properly.


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## TreeSurfer (Sep 27, 2012)

thinking im gonna just do all the "gaskets" while im at it.

Bailey's - Chainsaw Gasket Set for Husqvarna 394/395 Chain Saw 

this damn saw is nothin but trouble. i have done everything to it except the main case gasket and buy a husqy case splitter and a few extra bearings just in case they are bad and need to be replaced. 
i have been super hesitent to drop more money into this saw since i ebay'd it for $600 and had to spend another $500 into ti just to make it work at all. i know i got scammed but at this point i think its worth it to just make it run. been slowly putting parts into it and not doing it all at once. was getting more use outta my 441 for a long time and havent needed my 394 until i started working for a tree care company here on the island. he goes from a 359 to a 3120. there is no in between saw. :bang:


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## lone wolf (Sep 27, 2012)

TreeSurfer said:


> what are the signs of a bad crank case seal? how will the saw sound or run?



Troubleshooting Air Leaks

A crankcase air leak is a problem many pro saw engines have at some point in their life. Symptoms include: over reving, overheating, stalling on acceleration, failure to idle, and worst of all, an engine seizure if the problem is neglected.


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## Gord404 (Apr 10, 2018)

Toasted a piston and cylinder on my 390 xp recently from a leak (hole) in my pulse carb line, ( someone working on it before I got it bent the brass crankcase nipple down and caused a hole in the line, why, ????) symptoms were not being able to set idle properly and overheating till death of piston and cylinder, vacuum and pressure test were good after fixing that problem so it, up and running again - costly mistake - part of the learning curve, just joined the forum, a lot of knowledge here Thx - Gord


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## HarleyT (Apr 10, 2018)




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