Hello i have a 2004 400ex. I have a list of mods on it already and wondering what people think i should do next. I have HMF slip on exhaust, K&N filter, Dyno Jet jets, Hotcams stage 2 hotcam, Weisco hi comp. piston, ac bumper, ac nerfs, moose bars, pro grip grips, and pro design kill. I was just wondering what i should do from here on. I am thining about sending my head into FTZ and getting full system sparks exhaust, possibly the 440 kit but i have heard bad things about them so considered 426 instead, diff carb also in mind and thinking bout suspension just wondering what ideas people had ty for the help

 

Sounds like you got a lot of money in that thing Yagerbomb. You could spend more money for a big bore or port and polish job to gain hp. You could spend it on the suspension for better handling. But, no matter what you do it's not going to be on par with a 450 and it sounds like that is what your after. By now you've spent enough on this thing you could have a sweet 450. I'd try selling it or holding off until you can sell and get a 450 because your going to keep pouring money into this thing to get the performance your looking for.

With that said if you do get an exhaust for this thing let me know if your selling your HMF slip on. I need one my E-series is bashed up and coming to end of its life.

 

Ok thank you ya i know when i built my 400 i messed up i shoulda saved for a 450 and i am well aware of my mistake lol and yeah idk if i want the 450 just getting into racing so i want to get it down on the 400 and if i can start to drive better than i can now u 400 is just as competative as a 450 at the track im on... lol a 440ex won the 450 class...

About ur exhaust issue... um yeah i wouldnt mind selling it im thinking bout full system sparks neway... so let me know what u willing to pay for it thanks alot for info


2004 400ex
HMF slip on
K&N
Dyno Jets
Hotcams cam
Wiseco piston
Moose bars
AC nerfs
AC bumper
Pro Design kill
Pro grip grips
and i might b forgetting something
Thanks to my sponsors
AMSOIL, Fatmax Racing, Tekbolt

 

Also i was wondering how reliable ur 440 was for u and if u have had ne head gaskets go out or anything like ur piston skirt craking... i am considering a 440 for mine... what piston did u use wiseco cp... i feel u r a resonable source and appreciate the help thank you

 

Also i was wondering how reliable ur 440 was for u and if u have had ne head gaskets go out or anything like ur piston skirt craking... i am considering a 440 for mine... what piston did u use wiseco cp... i feel u r a resonable source and appreciate the help thank you

 

About the slip on. Truthfully I don't have the money for one. I'm living with mine until my bro sells his 400ex and i can swap ours out. I can spear $100 or so if your willing to take but thats up to you if you need to get rid of it.

Now about my 440. I didn't build mine. I bought it from a guy who told me it had a 440. I really don't think it does and need change my sig. My bro has a 426 bore (all other mods same as mine) and ours are dead even. We ride with a good size pack of 400EX's and we are by far the fastest.

I'll give you an example of me vs a 450R. The '04 450R is geared down slightly, bored over (not sure of sizes on 450). Slightly upgraded cam. full Yoshi exhaust. In a drag I'm right with him until I shift into 4th where he slightly pulls up when I shift into 5th he pulls away. 450R's are much higher geared so this is expected but I surprised I hung with a machine like that that long.

So in summary. If you go with a 426 with your cam (I'm not cam'd...Yet). You would be an even better match. Plus I know the 426 is solid and you don't have to re-sleeve. (That's another reason I don't think I'm 440. I supposed to believe the guy re-sleeved but didn't know enough to jet the carb after put on exhaust..Idiot.)

Question I have for you is your cam is stage II? I would think you'd loose bottom end with a cam like and stock compression. I had decided for a stage I because my understanding was the stage II was all top end power (but lots of it) and I wanted more mid power than top. Can you agree with that?

 

What type of piston does ur brother have in his 426.... did he go with wiseco or did he use cp pistons. Neway i wont sell the hmf for 100 that just isnt enough but it is still for sale for neway wondering.

2004 400ex
HMF Slip on
Dyno Jet jets
K&N with outerwears
Hotcams stage 2 cam
Wiseco 11:1 piston
AC nerfs
AC Bumper
Moose bars
Powermadd handgaurds
Pro design kill
Thanks to sponsors
AMSOIL, Fatmax, Tekbolt