White Brothers Slip on Silencer

I'd like to have input on the White Brother's slip on silencer. Are jetting or airbox changes required to run this silencer? Is it quite a bit louder than stock? Any noticeable power gains?

Mitch
02 Yellow 400 EX

[Dave400ex]

If your looking for a new pipe I would get the Sparks X-4 full pipe. It had the most power in the ATV Sport test and weighs 2 pounds less than the White Brother complete. Check out sparksracing.com. He makes a complete hop up package that includes a sparks foam filter with ring to keep it tight, a mod for the stock airbox, advance key, high rev CDI, and the X-4 complete exhaust all for $609. Depending on your budget I think that`s the way to go.

[Razorback]

Mitch - I've had this setup. You are not required to change your jetting or airbox with just the WB silencer. It is quite a bit louder than stock, but the sound is great! Nice, throaty 4-stroke sound. You will notice some power increase with just the silencer and no other mods. It won't be mind boggling, but noticable, especially in the mid-throttle range. I found that I was running a little lean, so the motor was hotter than stock. I have now rejetted mine and put a hole in the air box lid and the power increase is much, much better - very noticable over stock, especially half to full throttle. The motor is running a little cooler now since the jetting is better.


By the way, I went to 160 main, 42 pilot and raised the needle one notch. If you are trying to determine if you want the WB, I would definitely go for it. I'm very pleased with mine. Keep in mind that you can adjust the exhaust with the removable discs. Good luck!

[400exRacerX]

i have the slip on and i ran it with the stock jetting and it backfired, it was running too lean. so i rejetted, whats the big deal if you have to rejet? its fairly simple, just read the thread "help jetting a 400!"