grasshopper sucks oil into breather

heron

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I have a 718 that runs fine but sucks oil into the air breather which then clogs the air filter. if a put in a new filter it runs fine again for a few hours until that filter gets coated with oil. The dealer will only tell me i have to bring it in for them to diagnose. can't afford that. =) im sure its a simple fix once i figure out what to fix...
 

ILENGINE

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Most likely causes are blowby. Which could be worn, bad rings, blown head gasket, or possibly a broken breather reed. Which engine do you have on your mower. Model number helps us to narrow down the possible issues.
 

heron

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it has a Briggs, Vanguard 18hp gas Vtwin engine. model number 350447 there is a crankcase vent in the middle of the air filter where it sucks the oil from.
 

ILENGINE

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The breather housing is located under the air cleaner attached to the block with a single bolt in the middle of the V between the cylinders. that is were the breather reed is located. Other reasons for your issues could be a blown head gasket or worn, broken rings causing pressurization of the crankcase.
 

heron

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The breather housing is located under the air cleaner attached to the block with a single bolt in the middle of the V between the cylinders. that is were the breather reed is located. Other reasons for your issues could be a blown head gasket or worn, broken rings causing pressurization of the crankcase.

i found the breather and took it off, cleaned it, it appears to be fine, gaskets are still pliable and not brittle. how do i test it? the reed opens when i push on it lightly. i thought it was a one way valve so i tried breathing through it, it doesn't seem to be one way.
 

ILENGINE

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It is a one way valve, but isn't air tight so it won't hold pressure. Sounds like you may need to do a leakdown test to determine if it is rings or head gasket.
 

bertsmobile1

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clean the air filter end of the tube then blow and suck ( yummy ).
You should be able to suck but not blow .
And just to be picky, the breather tube BLOWS using crank case pressure the carb does not suck from it.
 

heron

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clean the air filter end of the tube then blow and suck ( yummy ).
You should be able to suck but not blow .
And just to be picky, the breather tube BLOWS using crank case pressure the carb does not suck from it.

I can do both. easier to blow actually. i will go to the grasshopper store tomorrow. i am guessing that means the reed valve assembly needs replaced.
 

bertsmobile1

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I can do both. easier to blow actually. i will go to the grasshopper store tomorrow. i am guessing that means the reed valve assembly needs replaced.

Yep you got it, new reed valve.
You still might be suffering from blow by or a leaking head gasket , but one thing at a time works well .
 

heron

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i replaced the reed valve and it helped but didn't fix it. turns out there is a 40% loss of compression in the left cylinder due to the rings and some scoring... thanks for the help!
 
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