MX Motor

[EXflattracker8]

Okay guys I know this has been posted a thousand times but please be patient and read. I am wanting to build my 400ex motor into an all out motocross monster. Money is not an issue although racing is in full swing right now and I am wanting to get it done on one of my 2 week break periods. I AM NOT sending my motor anywhere instead I want to order the parts my self and have the guy whos race team I am on build it for me. He does porting so thats a good thing. I already have the basics( duncan fatboy 4 pipe, k&n filter/jetting). I want to know a list of parts and prices that I should order to give me a killer MX combo. Thanx guys!

[4TraxRider]

A high compression piston, cam, and a carberator wouldn't be a bad start.

[AtvMxRider]

What kind of suspension mods do you have?

[EXflattracker8]

Elka Shocks, +2 burgard arms, and in the rear a lonestar swinger

[bigfoot300ex]

do you have that yellow 400ex at foggy bottom and you usually race paul lucas if so i will be in your class this coming saturday
r u going to do the fall series
you might have seen me there before with brandon rushing

did paul ever get his raptor running??????

[mx400]

go to Sparks Racings website and take a look at their 416 national kit. i am going to be using the parts from that kit for mx and a couple of people that i have talked to that have this kit that race mx love it and say has plenty of toque and gobs of top end. very nice kit they say

[trx400ex]

pull the motor out of the frame, junk it, and put in a crf if money isnt an option, otherwise call a builder and they will give you advice and sell you what you want

[skemp]

If I were going to do it right...

-TC MX grind cam (or similar grind)
-Hardened rockers/HD valve springs
-Porting
-440cc bore (I would bore to 426cc and then stroke to 440cc if time allows)
-13:1 compression piston
-Carillo HD rod
-True and weld crank
-Heavy Duty head studs
-FDO Heavy duty timing chain
-Complete Hinson clutch
-FCR 39MM carb
-Large capacity oil res.
-FST oil cooler
-Hetrick Racing rev box

You WILL be happy, and have a much greater edge on the competitors.

edit: forgot to add a few things

[mx400]

not a bad setup skemp. but imo the sparks 416 nationals kit is way more better. u dont have to mess with all the problems big bores can sometimes create and u wont have all the vibration a 440 big bore makes with a 416. plus sparks 416 kit will outrun most if not all 440s. my buddies sparks 416 national motor has outrun 440s so many times on a track and strip its not even funny. sorry not gona start a flame just sayin

[skemp]

Well, no doubt a 416 can blow a 440's doors off. But this depends on how well the motor is built. A 416 (like mine) with all the goodies I mentioned will eat a 440 with simply a bore and cam no problem. The 440 can just have a bit more torque over the 416 which can mean a lot on a mx track. Besides, I believe I mentioned all the parts that come with the National kit from Sparks. Either a 416 of 440 will have awesome power, but there are some minute differences, namely in where power comes and how it is/can be used.

[Bender]

I agree With TRX 400EX, if you got the cash you say you do. Buy a CRF engine.