i just bought a 2000 400ex and i plan to do full exhaust and a front sprocket. i have narrowed it down to either the pro-circuit or the yoshimura..what do you guys think? also, what tooth is the factory front sprocket? thanks

 

I prefer the yosh it looks good and sounds better .....On the sprocket i believe it is 14 tooth front and 38 rear ..If yo go smaller on the front you are more apt to wheelie and we know how wheelie happy the 400ex all ready is ...Back to the yosh pipe it made more hp and torque on the dyno in indiana compared to the DMC which it supposed to be the S@#T for he 400ex ..And the yosh is cheaper GOODLUCK WITH what ever you decide ...RIDE RED OR YELLOW............

 

The stock front is a 15 not a 14. I just wanted to clarify that.

 

so if i get the yosh full system and a 14 front sprocket can i beat a stock banshee? just a thought

 

You will not see any difference on a stock 400ex if you change the head pipe, if you do more mods later on and you have the money then go for it, but for a stock 400ex dont wayste your money, just get the slip on. A stock Banshee puts out around 38 hp and a stock 400ex around 26-28, You will need to do a lot more than just the exhaust to beat a Banshee in a drag but on MX or trail riding i love my 400ex.

 

I've been having a you know what of a time chosing a pipe for my 2000 400EX. Everyone tells me somethin different about every pipe. Everyone says go with the complete system, but I heard also that the EX already had a good head pipe on it. I want a pipe for some low end power and the noise, if I just put a slip on on like you said will this give me any more bottom end?

 

Well i added a Pro Circuit slip on this week and i went riding this Sat and it sounded great and looks great but i really could not feel any difference, i have a 155 main jet on but i am going to go with a 165 with no air box lid and move the needle position and well see how it does. I raced a guy with a Yoshi full system when my 400 was stock and he beat me only because i popped a wheelie in second, once i got the front down he didn't pull me that much, maybe a little.

 

That is because aftermarket pipes do not make a 400ex faster. Look at GT thunders tests on the 400ex. Pretty pathetic for as much louder as they are. If you want to go faster, get a 416 piston for $160 and a xr400 cam for $120 and rejet and keep the stock pipe. It will be stealth and alot faster than a piped 400ex.