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Outdoor Power Equipment Guru
Outdoor Power Equipment Guru, Technician
Category: Small Engine
Satisfied Customers: 540
Experience:  I have worked twenty years as a Mechanic and am a State of Michigan Certified teacher in Small Engine and related equipment.
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My 16 HP Briggs and Stratton Vanguard V-Twin continually gets

Resolved Question:

My 16 HP Briggs and Stratton Vanguard V-Twin continually gets oil in the air filter box, enough to soak the filter. The oil is not too full and I have already replaced the breather valve. Wondering what else might be the cause?
Submitted: 5 years ago.
Category: Small Engine
Expert:  Outdoor Power Equipment Guru replied 5 years ago.
Hi my name is XXXXX XXXXX I will try to help you with this.

Vertical or horizontal shaft engine?

What is the application?

What weight oil are you running in it?
Customer: replied 5 years ago.
Horizontal shaft on a Jacobsen Greens King IV Triplex. Amsoil 10w-30 synthetic oil
Expert:  Outdoor Power Equipment Guru replied 5 years ago.
Im assuming this does not get run on too much of an angle?

Does it tend to get real hot when it runs (more than you would consider normal)?
Customer: replied 5 years ago.

Mows mostly golf greens so not much of an angle.


With no temperature gauge it is hard to say, but I don't think it has been hotter than normal. But if it was running hotter than normal would that mean something?

Expert:  Outdoor Power Equipment Guru replied 5 years ago.
wellll these engines are widely used and I have a lot of experience with them and this is a common problem that I see but they are run on varying angles to which I attribute part of the problem.

You have covered the basics the other issue is if there is any gas getting into the oil this can occur if the diphragm is bad in the fuel pump (unlikely but possible) or the unit is running with the choke partially on or idles alot and is set too rich.

if there is gas in the oil you should be able to smell it easily.

What I have done on several of these is simply underfilled them about a cup to lower the oil level as the crank tends to hit and aerosolize a lot of oil in these units which is sucked up the crank vent and subsequently into the carb throat/air filter. Once the filter gets any oil in it it begins acting as a choke and drawing oil in making the problem worse. Once this has happened you definitely have some oil/gas contamination which has to be drained and changed.

so the only actual fix I have come up with is to lower the oil and add lucas treatment to thicken it slightly and give it a clinging property to prevent any possibility of low oil.
These sumps hold more oil than the engine needs so lowering it is not an issue.

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