nothing will make much power if any unless the bike is jetted correct. the sparks system will make more power than the fmf but if money is a concern, there are other ways to go. for example, you could put in a high compression piston, hone the cylinder wall, put in a drop-in cam and still be around the same price as the exhaust system. the cam/piston combo will give way more power than an exhaust system. so it just depend on what you looking for. as far as the exhaust goes, i would say sparks is the best out there. the sparks will make more power but by just adding a new pipe, don't expect anything dramatic.

 

The sparks is a great pipe easily the best 4-stroke pipe available today.
On a 300ex they require a bit of modding to fit, you are required to remount the rear brake fluid resivoir in a diffrent area and you also need to trim a bit of plastic from the inside of the back plastic.
Not a big deal but I just thought you might want to know.

 

Thanks deal

 

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i just got one on my 400ex , SWEET!- night and day differance in HP, i race harescrambles and used to loose alot of time in the firld crossing by the fast guys but not eatin that dust anymo!wink wink! VERY loud though..get it!