Burping a 912

[Keith W]

Sometimes I can't get my 912 to gurgle the oil back into the oil tank, usually it burps after about 10 turns but every now and again it won't do it, it's an 80hp in a Gazelle with plenty of compression, if I run it its usually burps next time I check it thanks Keith.

 

 

[Downunder]

Mine burps well before 10 turns. (Low hours but)

 

You need to turn it slow through the compression as it's the ring blowby that pushes the oil out......

 

My 2 cents anyway.....

 

 

[crashley]

Ours take quite a lot of turns to make it burp especially if you turn it fast it you turn it slowly and hold it at the top of compression it burps a lot faster

 

what is happening to the oil level when you cant get it to burp is it low on the dip stick or at the normal mark

 

 

[Keith W]

The oil level is low on dip stick when I can't get it to burp and I turn it over slowly holding it for a bit on compression which usually makes it burp in about 10 to 15 turns but sometimes it doesn't happen.

 

 

[crashley]

Ours seems to take longer to burp if it hasn't been flown for a while I think the longer it sits the more oil seems to accumulate in the sump which means longer time to return all the oil to the tank

 

cold weather also makes it harder to burp

 

 

[Guest Maj Millard]

Get into the habit of burping right after shutdown when the engine is hot. Go home then and check it next time you come out when it is cold. The oil level will always be there.

 

I never try to burp when the engines is cold.

 

 

[Downunder]

I think oil tank oil level in relation to sump level may make a difference too....

 

 

[pylon500]

I think oil tank level in relation to sump level may make a difference too....

Makes a substantial difference.

Gazelle oil tank is fairly high on the firewall so nearly 50% of the oil can run back into the engine.

 

Foxbat tank is fairly low, it will burp in one turn of the prop.

 

I think your Gazelle problem could be if you're using a low viscosity synthetic, could be running back as fast as you pump it?

 

I had heard (if it's not in the POH) to start the engine for a minute, shut down, then check the oil.

 

Not real clever in my books.

 

 

[ctfarmer]

Burping hot works for oil level checking prior to next start but i always like to turn the prop through a few turns before start as this operates the oil pump supplying oil into the engine so bearings and valve train start under fresh lubrication.