Will extending my exhaust on a 3hp give my engine more power?

I hardly look at the age of a thread. Because the info within it is not only relevant for the original person but for anyone else in the future to read and take advantage of. Her is a Pic I found in a kart catalog I have to back up my answer to this thread. Stock or modified will benefit from a header. Not only this certain one but most all will have gains, and even more if steps are taken to tune for it instead of stock muffler i.e. jet size and or carb screw adjustment. 20210827_135315.jpg
Here is the most frequently used items in my header collection. As you can see I use 3/4 inch plummer pipe for attaching headers. I simply tap the header for the pipe and die grind the plumber pipe ID out quite a bit. I also bought all the different lengths up to 6 or so inches long that way I can experiment with different torque bands, top speed etc. Depending on the day and the jetting I have found most of the time the flared end type produces more desirable outcomes only thing is they are quite loud. Especially once you get the annoying backfire tuned out of it. Letting off at WOP throttle makes for some pretty impressive music for a 3hp. Sometimes the m 90 silencer (stock) will get the engine to really come to life on a cool summer night. Once I get it all back together I'll see about posting a video one running down the road. Any questions on this topic feel free to pm me or reply and I'll be glad to give you my 2 cents. Thanks Don