Briggs & Stratton pumping oil out of the exhaust

[MrNick]

The B&S 5hp engine on my dads dr trimmer mower is pumping oil out of the exhaust when started. What are the likely causes? There did not appear to be any metallic glimmer in this oil. Not over full either. Thanks 

[Ratman]

https://briggsandstratton-aem63-prod.adobecqms.net/eu/en_gb/support/faqs/browse/engine-problem-solving-tips.html

[MrNick]

Thanks but that's no help to me. B&S quantum 5 hp engine

[dumper]

Have you tipped engine over? If not rings or valve seats?

[Ratman]

Have you tipped engine over? If not rings or valve seats?

As described in blue smoke literature. Be a storage fault or valve/stem seal/cylinder gasket issue at a guess.

[Baldbloke]

A burnt away exhaust valve face can certainly pump out a bit of blue smoke too[emoji3]

[lurkalot]

Does sound like it's been tipped over.  Any signs of oil in the air filter?

 

It won't be Valve seats, or valve face causing it though, that's not a thing.  Worn Valve guides or Stems will leak a bit of oil, but not usually enough to cause problems like this. 

[spudulike]

I don't know the engine but typical faults causing oil burning are piston/ring/bore wear that cause blue smoke all the time, lack of power and excessive oil consumption.

Oil leaking from a gallery/oil feed cavity due to a gasket failure can cause oil to enter in to the combustion chamber.

Oil leaking down the valve guides usually gives a good old puff on start up and will clear but get bad if an engine is left running slowly for a period then revved again.

A crack in the top end casting can cause issues with oil.

If it is mostly on start up and the engine isn't using oil excessively, suspect worn guides or valves.

Learnt from Japanese rice burner bikes in my teens