I have a 20hp Briggs&Stratton used riding mower. I don't have a service manual so I need to know what oil weight and spark Plug and gap it takes for a tune up. Model #14AU844H401 46in. cut 14 speed low/high
Usually a 30 weight hd oil is good and name brand is up to you.
Plug gap is uaually set right but ya never know when its been dropped ect.
Change oil when tractor is HOT ...its like cooking grease when its hot ..it will come out with ease ,,,,,,,cold it just drags out .
If ya look on internet under your tactor you will proably be able to find service manual ....I found service manual and parts list with explode views for my Craftsman riding mower ...good luck