I installed the Powerbomb and it increased the upperend power but reduced the low end torque.

 

All I know from what I learned years back, selling the KLX300 was that the way for more power on it was a header and a carb. The head pipe was restrictive and the carb flowed better too.

On my own KLX650 the full exhaust freed up breathing and performance so much that I actually gained MPG. I also did a big bore to a 678cc. I get 60 mpg plus/minus a few miles regardless of how I ride the bike or where I ride the bike.

 

I think if you're going to go with a bigger displacement of 300cc or a bigger kit, it's definitely worth it. Unlike FM Thumper's results, I think the better head pipe actually improves low end. Still, the powerband influence isn't any one element. It's the sum of its parts...like jetting, airbox mods, carb, muffler, etc.

 

The Powerbomb is supposed to increase the high end and the megabomb is supposed to increase the low end. When I got my header, the megabomb was not available or I probably would've gotten the megabomb.

 

Ah, I see. I missed that you were talking about that specific model.

 

My powerbomb added low end grunt without hurting it anywhere else, makes roll on wheelies alot easier. This was on an 09