How to make my 400ex out run a 450r and predator

[03'400exrider]

I have an 03' 400ex, it has a 11:1 compression piston, HMF exhaust, stage one hot cam, k&N air filter, and a 16tooth front sprocket.....the main people i ride with (my brother and brother-in-law) have a 07' 450r and a 06 predator......both of them are stock except for a slip on exhaust....right now, we are EXTREMELY close in a drag race (the 450r does better than the predator by just a little)....im wondering what is next on the list for me to do to my bike (and just hope like crazy that they dont do anything to their bikes)............ive heard alot about a fancy CDI box that is adjustable to curve the timing......what are your opinions??????????????????????

[2002Honda400ex]

Stage two cam, port and polish, stroke it and you should be able to beat em:D

[blasterandy]

I say big bore(stroke) if you really wanna fuc em up get the CS 465 kit :D , stg 2, p&p, Make sure you have a full exhaust. But where does all this power go are you only drag racing or what. I would go with suspension before you are strictly for engine mods.

[pats2007450er]

i have a 588 in my 2007 450r wanna race

[pats2007450er]

just jokeing lol:D .no one can realy talk chit because every one on the 450's rode the 400's to.the 450's havent been out that long.if your going to race a 450r or predator your ganna need some work.just like blasterandy said port and polish head,bore it out,full system exhaust,stage 2 cam for mid-top end,uni air filter,maybe power lid,and a big jet,but if your going to build a nice size motor i would get a bigger carb.when you build a motor like that it's less reliable,but it will be a screaming demond.but your question was what's next on the list.if i was you i would get a port and polish done.thats where you find the power for a cheap price.are you racing 300ft or all out.

[Ruby Soho]

if you go big bore, such as 440 and up, get a stage 3 cam. port & polish, and full pipe.

then you should smoke em

[REPOMAN]

nitrous :D

[Old Head]

Turbo:devil: Just kidding, is a drag the only place you lose? Cause if your right behind them everywhere else then i'd go with suspension.

[250x_kyle]

use the search button there are so many threads on this... :devil:

[jordan_m6]

If the others stay stock

A Hotcam stg I
11:1 std bore piston
CDI
A slip on Exhuast
And the rider mod, should get the job done.

I can stay right on the rear grabbar of a 450r, that has a 14.5:1 piston, stage I cam and full exhaust.

I have also added the 450r carb, but have not ridin the bike. Its been sitting since last fall.

[maddmatt02]

does the guy suck at riding the 450r? is it stock filter/exhaust with a 14.5:1? also from what ive read/been told the higher the cr the lower your revs drop cuz the engine has to work so much harder to turn over that it wont wind up as high anymore. so maybe when he shifts to 2nd hes going to low in his powerband.

congrats if none of the above true but it sucks for me if it is, cuz I am not sure how fast a 04 YFZ is compared to a 450r, and not sure if youre talking of 04/05 or the 06/07's.

because if you put a certain 04 yfz w/ K&N/DRD pipe/jetted, and -1T front with everything I got I am about bike or so behind the grab bar. hopefully the carb will solve the problem though, and then my stg 3 cam will really fix it.

read of a guy with a 426 that hangs with piped 450's with a 41fcr so hopefully the carb does what I think it may.

[dragex400]

Bump up to a stage 2 hotcam, drop 1 tooth in the back with the 16 on the front(if you have 20" tires), and get a port an polish job done, and get a rev box for now. DO NOT GO WITH THE DYNATEK programmable igniton. I've been through five of them so far and my 400 keeps burning them up and I talked to people all over the country and no one seems to know why. I am currently trying to get a MSD programmable ignition wired up and hopefully it works better than the DYNA. The timing curve will really help but from my experience go with the rev box and just get you rpm's higher.

[maddmatt02]

ok, question for the topic starter, is there an aftermarket case saver that allows a 16T front? right now the 15 barely fits inside the stock saver.

[dragex400]

Yeah, I think ProDesign makes a billet case saver. Check it out.
http://www.prodesignracing.com

[450Rchaser]

I'm not saying I can outrun a 450r but I can keep up w/ my brother in law"s 450 that is piped, jetted, and got a 14t front sprocket. In certain gears of a about a 30 mph punch and can jump all over him about 2 lengths b/c my 416 revs so fast. Its possible to out run a 450r w/ minor mods. don't get happy and try to run up on one w/ a 500 kit.

[maddmatt02]

does your 416 rev like a YFZ? man those things wind up RIGHT NOW when you nail it.

[HurleyBraaap]

Originally posted by REPOMAN
nitrous :D


lmfao haha you'll need lots of it!!! with all the mods

[450Rchaser]

Nope, never rode a YFZ.

[WhtPrd09]

look at my sig for my mods. but i can beat a 450r and im half a bike behind my friends 06 pred se. but his is mildly built. i race a pred with a wb s/o k&n filter and jet kit and smoked it by 2.5 bikes. my next plans is head work so that should get me up there past him.

[maddmatt02]

stock 450R?, 40/05 or 06/07?

and isnt 15T stock?

[CDCHONDAS]

seems to be alot of poor riders around it is possible to beat a 450r without stroking and heres things that will bring you up with a piped r that is running well

head porting
440 with good piston oh yea i like low compression too. probably not a wiseco
very good exhaust
+1 on the countersprocket
open air box
larger carb preferably 5-6 hundred bucks (you know which one i mean)
cam, seems this is where people always cheap out, you can put a hc in and run very good but theres better stuff out there.
somethings like con rod and heavy timing chain are optional, as well as studs since its fairly low compression, heavy studs are better, not required

I also really think I could similar results with less cc but theres no replacement for displacement.

[vett_09]

Originally posted by maddmatt02
stock 450R?, 40/05 or 06/07?

and isnt 15T stock?

The 15T is stock on the older 400's. The newer ones (04 or 05, I can't remember) have 14T fronts.

[maddmatt02]

im not a poor rider, and her YFZ is quick. and if +1 will help, would -1 hurt? seems like it would be best to drop one for acceleration, or should I have such low end I should be pulling the same gear longer and shift less? although shifting doesnt take much time. I found a case saver I can run a 16T with but I dont wanna spend 50 more right now to get the sprocket and saver. anyways last time I had a 38mm PWK(think thats what is stock), no airbox lid, and ran 14/38, this time Ill have basically no airbox, port matched IM, a 39mm FCR and running 15/38.

if I was only 2 bikes at most behind before by 5th gear I think I should take her. if her bike topped at 73 before( according to dirt wheels) now that she dropped a tooth shewill be high high 60'S maybe? wont the 400 ex hit 70 something if you can pull to the rev limiter?

I am planning on getting her this time.

Im thinking of LRD pro4 full system some day, also I am going to eventually get oversized valves and have the head further ported and a wilder cam.

[maddmatt02]

also not sure what kind of gainsit gives if any besides being able to run higher cr, she runs rtech 106 or 108