what are the top ten upgrades for a 2002 400ex?

 

Ya that is the same question that I am looking for KINDA...What mods can I do to my 400ex to get the max HP without getting into the motor....

 

You aren't going to get that much power just thru bolt ons. Once you start modifiying the internals the 400EX really wakes up. Here is what I suggest just bolt-ons.

Slip on Exhaust, ( with stock internals you lose alot of torque going with an aftermarket head pipe )
Uni or K&N air filter, with prefilter.
Remove airbox lid or drill holes in it.
Rejet carb, or go Edelbrock Qwicksilver carb.
Hinson billet clutch basket and pressure plate.
Replace weak factory handle bars.
Shave the front plastic, (less weight and wind resistance)
New tires and rims.
Aftermarket suspension.
Aftermarket chain/sprockets.
Aftermarket axle.
Lighter hubs.

Everything I listed above is without getting into the engine, they will improve the all around performance because of less weight.

Things you will notice the most are:

Higher Compression piston, 416cc or 426cc piston HIGHLY recommended.
A good cam and stiffer springs.
Ported head.

There are more but I am tired. I will get to them later.

 

why dont you want to get into the engine?

With a whole exaust system (pipe and headers) you can get a lot more power
Mod the air box, K&N airfilter, new jet for the carb, and port the head. Porting the head gives ur motor more air. Its not like you're boring the enjine. Do all of that and you'll have a much faster bike.

 

how much money is that all going to cost?

 

My top ten upgrades.....I'm going off my buddies 400ex because it runs strong....


1.) Wiseco 10:1 Standard Bore
2.) Stage 2 Hot Cam
3.) Barnett Dirt Digger Clutch
4.) K&N Filter with outerwear
5.) Alba Slip On Exhaust
6.) Alba CDI Rev Box
7.) Durablue Lowering Kit
8.) 39/41mm FCR Carb
9.) Port Work
10.) Graphic's Kit...so it looks as fast as it really is.

 

porting the head: about $200
full exaust system $300-$600 dependin on the company. most are about $375-$450
air box mods are free, u do that urself
the jet is $2.99 , u dont need the jet kit, just the jet.

 

These are the basic things I do:

Full Chassis and Swingarm Skid Plates
Bumper
Rims and Tires
Handlebars
"Desert" Fuel Tank
K&N, Header and Muffler, and of course a Rejet
Aftermarket Suspension
Axle and A-Arms (if necessary)