Hey guys, i just got myself a 400ex. Its pretty sweet. First of all the only thing i found that i didnt like about it was the fact that the swingarm skid is really low to the ground. I had a blaster and didnt have as much trouble but i'm thinking goin to atleast 22 inch tires. I don't know if the 23's would be to big. Also maybe just to give it a little gidi-up my friend thinks the cheapest way to go is to put a rev kit in it. I'm thinking its not such a good idea for it to rev so high but I don't know. Take into consideration I don't want to put a pipe on it, atleast not at the moment. I'll prolly put a k and n air filter in soon so don't say that. I don't wana do really any big engine mods.

Thanx guys,
Email or im me at Pauleo21@aol.com

 

Everyone I Talk to says to go with a 14 tooth front sprocket. I havn't done it yet but I intend to very soon. My 400EX is stock except for tires(22 inch RAZRs)and an axle and it will barely pull top speed anyway. A 14 tooth should be a good investment for what it costs. Between $7 and $25 depending on which brand you buy.

 

A rev kit dont make more power, it just lets u stay in whatever gear your in longer. 4 instance if your riding trails and you are in third gear going into a big turn you would have to downshift on your machine,while if you had a rev kit, you problaby would have not had to shift to third in the first place.It gives 1000 more RPM and boosts your timing by 7 degrees. Try it, it makes a big difference.

 

Remove the spark arrestor from the stock pipe, cut a few holes in the air box and re-jet the thing. Sprockets are also cheap and effective.

 

with cutting holes in the airbox, how do you know what size jets to use? is it just trial and error?

 

Plug color. Start rich and work your way back.

 

A new air filter, pro-flow or K N is also a good idea. If not ensure the one you have now is always clean. Check and adj. your valves regularly as if these are off you will loose ponies.

 

Protection first. Full PRM skids, shock covers, ac bumper, ac nerfs.

Engine mods: pro circuit pipe (or other), k&n filter, dennis kirk stage 2 Hot cam, did chains dont wear as much, and its a pain to adjust all the time, so get a d.i.d chain.

some other things: drilled air box, splitfire spark plug with rev box, re-jet, and if you ride at night or in the dunes iv tried these and they rule. BAJA DESIGN LIGHTS!

if you ride in the heat, you might want to cool down your engine, try some (wrong name?) gcd or tnc (tnt?) air scoops.