Briggs recommend engine oil for this. However, 4 drops of a very light oil would be OK, as the drop volume is smaller.
On the subject of fuel, Briggs diaphragm carburettors aren't at all prone to gumming up. But E10 fuel is to be avoided.
Debris in the tank can obstruct the screens on the pickup tubes over time, and is the most common problem with them.
Cheers,
Gadge
"ODK Mods can explain it to you, but they can't understand it for you..."
"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."
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