What Briggs and stratton carburetor would give a 11hp most power ?

what b&s carb would give a 11hp most power

Instead of putting a new one on, try boring out the original one, as long as it's the older one piece carb. Just use a sanding drum and a die grinder. Make the intake port on the carb a bit wider and more velocity stack shaped. And try and round out the sharp bend inside the manifold part for better flow. Just be sure to clean it out really good before re-installing it, and you may have to adjust your mixture screws to get it to run right. Just a suggestion, but if you try it let me know how it goes!

You can do what AlliskidD21 said, it will do something positive to the way it runs but probable won't notice any change. Trying to get more performance out of carbs, if you do it wrong can be frustrating. Need to know what kind of performance you are after. No such thing as all around better when it comes to carbs.

Examples of performance would be based off what you have already. You are not liking something so this part is real specific.
Example 1-low end power, from idle to about 1500 rpm
Example 2-mid range power, 1500 rpm to about 2300 rpm
Example 3- high end power, 2300 to max governor speed if still hooked up.

Examples are based on what you have now. Based on what you don't like. Keep in mind, a different carb won't do a drastic change in engine performance but bring out certain rpm ranges while hurting other rpm ranges. It's always a good and a bad scenario.

OK, When I refer to power, I mean torque, the pulling force you feel when accelerating and under load.

General rule on carbs apply here, then you can go and figure out what you need from here.

Choice #1 is a little smaller carb- better at low end power with almost the same mid range power with a sacrifice of high end power. Sacrifice of high end power means, would take a little longer to rev up at the top end if not limit top end rpm.

Choice #2 is keeping the same carb and modding it by polishing the barrel and runner and playing with the fuel pathways inside carb a little and doing what AlliskidD21 said to do but this is hard and limited considering what kind of carb you have with little results. Plus the engineers have made this the best choice for the engine because mid range power was what they were after.

Choice #3 is A bigger carb for high end power with a big sacrifice of low end power and a little weaker change to mid range power. Engine would have trouble idling if you go too big of a carb.

Ok Carb size is determined by barrel size, which is where the venturi is and the barrel is the pathway that holds the venturi. A bigger carb will have a bigger barrel and a smaller carb will have a smaller barrel as compared to what you have on the engine now. An easier way of thinking of barrel size is by the throttle butterfly. The bigger the butterfly, the bigger the barrel to match the butterfly since the butterfly is what closes off the barrel.

If you are thinking a better different name carb, their all made the same and do it the same way. Just getting the name.
Good luck on figuring it out.