entire atv build this winter!!

[trailrider894]

so i'm planning a entire rebuild from the ground up on my 2000 400ex. but i want to upgrade some stuff on the engine and everything else. i want some people to tell me some stuff that they have done to there 400ex's that worked. and if anybody's has any idea's to make it look better let me know.

[buster024]

Well I hate to say it, but that's what nearly every post on this site is about. Just scroll down for the last few weeks, and you'll get about 300 different ideas on how to improve the looks, as well as the performance of your bike.

My personal opinion is to upgrade your suspension first and foremost. It will make the biggest difference in your ride. That being said, the younger generation of riders tend to want engine mods first.....although I think you'll regret it after you get bounced around on the junk shocks that come stock on the 400. A guy with better suspension will beat a faster bike in many cases because of their ability to land, takeoff, and manuever much better than the factory set up allows.

Make sure you are riding safe as well. Invest in nerf bars, body armor etc.

Finally, decide what you willing to sacrifice. Are you willing to sacrifice reliability for speed and power? If so you can got to a big bore 440 (maybe a stroker even). If you want to keep the heat down, and reliablity up, you may choose a 416 kit (again with a stroker). There are several people on here that have 416 strokers that swear by them. So I've been told, one of the GT Thunder riders (who is running near the top of his class) runs a 416 stroker kit.

Build your bike around your motor, not vise-versa.

Most of all, enjoy the build!!

[trailrider894]

yeah i already have a upgraged and rear shock. i also have nerf's bumper, rear skid plate, bumber, handlebar's and full riding gear from the ground up. i really was already thinking bout the 416 (stroker) do you know who make's the most reliable 416 kit?? and what all goes into to making that happen ( i guess the actual work)??

[buster024]

I know at least one person who has been very pleased with the kit from Laz at GT Thunder. There's a ton of other racing shops around though. I've talked with GT myself as well, and I'm working towards the 416 stroker. I don't think you'd be that much behind the 440 stroker as far as hp's. I could be wrong, but for the potential reliability issues, a 416 seems to be a great way to go. You can always go bigger if you still want more, later on down the road.

[justin1022]

Originally posted by buster024
Well I hate to say it, but that's what nearly every post on this site is about. Just scroll down for the last few weeks, and you'll get about 300 different ideas on how to improve the looks, as well as the performance of your bike.

My personal opinion is to upgrade your suspension first and foremost. It will make the biggest difference in your ride. That being said, the younger generation of riders tend to want engine mods first.....although I think you'll regret it after you get bounced around on the junk shocks that come stock on the 400. A guy with better suspension will beat a faster bike in many cases because of their ability to land, takeoff, and manuever much better than the factory set up allows.

Make sure you are riding safe as well. Invest in nerf bars, body armor etc.

Finally, decide what you willing to sacrifice. Are you willing to sacrifice reliability for speed and power? If so you can got to a big bore 440 (maybe a stroker even). If you want to keep the heat down, and reliablity up, you may choose a 416 kit (again with a stroker). There are several people on here that have 416 strokers that swear by them. So I've been told, one of the GT Thunder riders (who is running near the top of his class) runs a 416 stroker kit.

Build your bike around your motor, not vise-versa.

Most of all, enjoy the build!!


im not sure about this but the honda a400ex stock hasd like 26 0r 28 hp if you throw a 440 kit on (not a stroker) and hot cams and a pipe im pretty sure you should be good o go o nthwee track you should be able to beat a 450 if your any good of a rider im not sure though but i tihnk with lall that you should be pusing mid 30s for hp if you want i wil let you no i will have this set up soon.. already got the pipe and hot cams just weighting on the 440 kit and heavy duty timing chain and it should be hear early next week.

[MtnEX]

Myself, I think this is one of the best looking quads of all time and have since the first one I saw.

The 450R had it topped until the change in '06... and the Gen II plastic on the '05 400EX was similar. But even though I knew I could upgrade to '05 plastic, in the end I choose not to for now because I've liked the '00 style so long... and for the lighting.

Right about now I am glad I did stick with it too. I wanted to do something... and man... right now I am looking SHARP with the Duncan Racing graphics kit w/seat cover, stickers, T-9 beadlocks and Holeshots.

So I suggest a graphics kit, stickers, seat cover, tires & wheels for looks... or new plastic if you NEED it.

For engine mods, I'd go slow, small and clean. Do all the clean trick mods that put up performance, and go up on bore/displacement slow.

Make it a clean and reliable mod quad.... and above all, accept the 400EX for what it is, and love it for that. If you are wanting to go extreme nuts with performance, get some other quad.

[trailrider894]

hey thankx man. that is what i was looking for. i guess i can't ask to much of a quad only made for a little.