20hp briggs an stratton riding mower want turn over but a half of a turn even with a jump

SOURCE: gas comes out of spark plug hole

You have a Float problem you also make have gas in oil.

SOURCE: engine on riding lawn mower surging

Dirty air cleaner.

Clogged fuel filter.

Replace or clean both...

SOURCE: Briggs & Stratton Briggs Stratton Intek V -

these are common for doing this ,if you dont want to pull it down and hone the cyl. then i would use a heavier oil say 20w/50and that will probabley solve your problem

SOURCE: we have 42'' Yard Man riding lawn mower need to how to change oil

it's a square head pipe plug @ base of eng. either right or left side of machine may also have a quik change fitting instead its black plastic w/ yellow cap

Testimonial: "Thanks for the info, you where right on the money.. I finally found it, its on the right side if you were sitting on mower. Thanks again!"

SOURCE: i need an owners manual for a brute riding lawn

This was very difficult to find, but I found it just for you! Please make sure you rate my answer 4 thumbs up! Thanks so much for understanding, it would be a huge help to me. I would be forever grateful if you could do this for me. To view the manual you will need adobe reader, which you can get for free from http://get.adobe.com/reader/ You probably already have it though, please try opening the file first and find out. Here is the manual / guide please give it a few minutes the file is quite large:

http://www.doitbestparts.com/MANUALS/BRUTE/7800583.PDF