Which pipe would be better for a stock 2001 400ex?
which one gives you more hp gains which one sounds better and which one is louder?

thanks

 

I PREFER THE YOSH ON MINE IT MAKES 27.3 HP WITH K&N FILTER AND JETTED....IT IS LOUD BUT SOUNDS GOOD ........RIDE RED

 

I put a R-Series on my 400, K&N, and a 152 main. Don't know how much power I gained but the dyno sheet that came with pipe claimed 2 hp increase. Noticed maybe a little after jetting, but nothin to write home about.

Parts are in for the 440 11:1, race cam, ported, and rockers. I'm hoping to see maybe 38-40 ponies. I aught to be able to break a leg with that.

 

Dirtwheels did a product evaluation on the yoshi pipe they included dyno results:
Stock 400EX- 25.4
400EX with Yoshimura RS-3 Slip on- 28.1

oh dirtwheels also increased the main jet up one size.

 

Just my opinion here... I think that you should research if the exhaust sticks out past the rear grab bar. Some of the aftermarkter silencers do. If it does, than I'd expect some damage to the exhaust when you flip it over backwards doing a wheelie, or just tipping it up for whatever reason. I believe that the Yosh does NOT extend past. My buddy has the Yosh slip-on, on his Warrior... it's a very nice silencer in my opinion.

 

The Yoshi pipe does not extend pass the grab bar. This pipe has the best fit and finish in the business!!!