Can I mod my stock 400ex pipe for real power ?

[AAAirbooorn]

I also want to keep the spark arrester in and the db's down.

[250EXking]

nope. just buy a one. they have bunches of pipes that add power and you can tune sound and power outputs.

[shamisc]

Yes you can. But it takes time and skill. First, grind your header welds for a smoother flow. Then you have to cut your silencer at the back and front welds and remove all of the restrictive baffles. Next cut the baffle out of the end cap leaving about an inch of it on. Carefully cut the spark arrester screen away from discarded baffle and weld it back on the end cap to keep it forest legal. Weld the pipe back together at the ends and put the end cap back in and you'll notice about as much difference with this mod as if you had bought a White Bros. pipe!! You will need to rejet carb b/c of course it gonna flow better than before. If you need more help with this email me at shamisc@yahoo.com and I'll hook you up!;) :D

[AAAirbooorn]

Thanks Shamisc, but can I adjust the noise level (without affecting the power level )so the neighbors won't call the cops?:huh