With a little searching you can find the owner's manual on line. In 60+ years of working with small engines, I have never concerned myself with how many oz. of oil they held.

Walt Conner

Yep--thats the way to do it--just pour in some oil, then pull the dip-stick, check it and if it needs more, then pour some more in! Careful wiping and checking will get the job done. Why worry how much ounces, or whatever, when ya have the dip-stick ?!
American short-cutting invented the dip stick. And, if ya really want to know how many ounces/liters/pints/quarts, keep a careful check of how much oil ya pour into the crank-case! Which won't matter, as long as ya don't fill the crank-case over the full mark on the dip-stick. SHEESH!

The only reason someone might want to know the capacity in ounces (or other meas) is because they might want to know how much oil they should purchase to do an oil change if they are not familiar with that engine.
Otherwise do what the rest of us do (as was already stated by 2 OTHER old men like me) :^)

Download the owners manual from the Briggs site.

Briggs sells at least 2 different length filters so that's a couple oz. difference. + you don't get all the old oil out so there's an additional difference.....

Jeez; you guys are just as funny over here as you are on the mower forum. You should get jobs in an oil change joint - that's how they do it too - put in some oil, check the stick, put in some oil....that's ignorance.

"that's ignorance"

thanks for the compliment saxman.

Walt Conner

***"that's ignorance"***
Naaahhhh! Quite to the contrary. Ignorance would be the case if one were completely clueless about how to determine the correct amount of oil to put into an engine.
Learning how to determine when enough oil has been added to the engine by reading the dipstick is nothing short of brilliant enlightenment.

Select the subject "18.5 H.P." engine from the chart.

{{gwi:328773}}

Here is a link that might be useful: Due conversions

Ignorance is filling it with what the book says it should take instead of the proper amount to the fill line!
What a punk!

Ignorance can be cured but stupidity is a lifelong affliction.

Whew- rough crowd! Don't you know dump one quart down and then fill the funnel once and there ya go!

Funny how many people ask questions on self-help forums when they can Google and get the answers quicker...

On the contrary. We've all done years of personal growth and therapy since this thread was started plus downloaded an app for our smart phones that all we need to do is scan the engine and specs come up on the screen. Ewalk even has a smart funnel which dispenses the proper amount of oil. He usually even drains the old stuff out first.... ;-)

I resemble that remark.

Bahaha !