400ex vs. 450r

[KIMMER]

Starting to build a project and I am looking at both motors (450r and 400ex) as possibilities. My question is, can the 400ex become a good 4 stroke drag motor? Also, with both motors modded with the possible big bore kits, can the 400ex be close to equal power? The only reason I ask is due to the price of items for both. It seems like I can buy a 400ex for next to nothing and the aftermarket parts are pretty cheap. I want to build a sweet 4 stroke drag bike, but still want to be competitive. Thanks guys!

a fully modded 400ex engine will barely surpass a stock trx450r engine. as soon as you start modding the 450r engines you just wasted your time with a 400ex

[KIMMER]

Looks like I better start saving for a 450r motor. Thanks for the quick reply!

Originally posted by KIMMER
Looks like I better start saving for a 450r motor. Thanks for the quick reply! mo problem...welcome to atvriders

kabam! BRAND NEW TRX450r motors for sale (http://www.trx450r.org/forum/index.php?showtopic=9989)

[JRP]

450r will walk away from it.

[12 o'clock]

is yoshimura the best to go with on the 450r or am I just paying for the name? Also what is the K and N air flow system the best route to go with

Originally posted by 12 o'clock
is yoshimura the best to go with on the 450r or am I just paying for the name? Also what is the K and N air flow system the best route to go with go with a Dr. D slip on if on a budget or a curtis sparks if you have the money. K&N's are crap, get a UNI

[cals400ex]

i have a sparks that i am considering selling. let me know if your interested.

[Iliketogofast]

Use a 250R motor if your building a drag bike!!! WTF!? I've neer even seen a 4 stroke drag bike!

[KIMMER]

I just started seeing a few drag bikes that are 4 stroke and thats what sold me. Guy had a yfz 450 in a trike and was whipping the crap out of people. Sounded pretty sweet too! I'm someone who always has to have something different that someone else, thats the reason for the 4 stroke. If I was going to go 2 stroke, it would be a KX500 in a tecate trike frame.:D

[red2004 TRX450R]

I would go with a shee or a crapter motor.

look a bult shee

http://www.geocities.com/gtthunder.geo/shephard.gif

and a bullt 440ex vr 400ex stock
http://www.geocities.com/gtthunder.geo/440exmod.jpg
stock 450r and yfz450
http://www.gtthunder.com/sitebuilder/images/trx450rdynorpm-650x487.jpg

[Blown 331]

Originally posted by Iliketogofast
Use a 250R motor if your building a drag bike!!! WTF!? I've neer even seen a 4 stroke drag bike!


When do I get to smoke your 250R with my 4 stroke?

id use a yzf or banshee motor for a drag bike

[Iliketogofast]

When do I get to smoke your 250R with my 4 stroke? Date, time and location. I'll be happy to had you your *** as long as you would be willing to make the mistake of showing up in one of my riding spots.

[Blown 331]

Originally posted by Iliketogofast
Date, time and location. I'll be happy to had you your *** as long as you would be willing to make the mistake of showing up in one of my riding spots.

Sounds like you want to beat me up or something. lol. :rolleyes:
So I name the location as long as I show up at one of your riding spots? We race on pavement for sure.

[Iliketogofast]

Lol... I know. We can't now, I blew my motor. But why the hell would you wanna race me on pavement? If I were you I'd hope and pray the 250's tires spun...

[KIMMER]

Well, went to the dirt drags today and needless to say....I will be buying a yfz450 motor. I watched a yfz450 eat every banshee including my friends built banshee, and every 250r except for one that the guy had custom built his own frame and ran nitro methane with nitrous. That 250r was insane! So far I am extremely impressed with that yamaha 450. I also saw a couple triple powered quads that were pretty crazy, but the craftsmanship was something to laugh at. You could tell these people were just throwing stuff together with no money.:huh