Inside the engine there is a governor that restricts the engine from reving freely thusgiving you the classic put put noise of a mower. Removing it allows the engine to rev up to say 5 - 6000 rpm (guess) and thats why a standard lawnmower can do 40+mph. As for removing it I recommend getting a copy of the workshop manual for your briggs and it will be in there, you will need a new gasket set too.

...also wat does removing the govenor mean, and how do I do it?
Cheers

Hello,
I have just bought a Westwood Gazelle, it has an 11hp Briggs and Stratton engine. I would like to get it going as fast as I can. Also where could I find parts for it? I need to get breaks, but I don't know what size or anything.
Many Thanks

hi where would i get a group 2 lawn mower and how would i prepare it???

Nice clip bud, I like the one with your boy. Check out me boy learning to fly. I also have a pansh ace 6 meter in red and white & radsail 3 meter good kite for the kids.