05 400EX, hop-ups?

[85ytz250n]

Well I just purchased a 05 400EX and thought that I would see what you guys suggest for mods. It is completly bone stock with very little miles on it at all. The guys son is in college and needed the money, so I came to his rescue. The tires still had the nipples on spots and the paint on the frame by the pegs is still like new. No mods to anything and I am thinking right now a filter and jet kit, would like a pipe but I cant stand a loud pipe. I also cant seem to find the VIN, can someone tell me where it is stamped?

Barry

[MRPoopie]

go to the front of the 400ex and look right behind the bumper where it mounts to the frame and it should be stamped there

[TravEX]

All of the aftermarket pipes are alot louder than stock.

Do a search, the mods are endless. Filters, pipes, jets, grinding down the headpipe welds, piston kits, carbs, cams, suspension, choke removal, etc, etc.

I doubt you would have to rejet with just a filter, unless you leave the airbox lid off.

Travis

[85ytz250n]

I am thinking bolt on mods for the time being, I need to get used to it before I start changing things to much with cams and the like. It is a definet change from the Z that is for sure. I was kinda worried about the VIN, didnt know if it was stolen or had been totaled and had a new frame. I think I got a good deal though, $3600 and its practicly brand new. WHich leaves me more money to mod it with. I was going through withdrawels while my Z is down so I had to get something to ride.

Barry

[MRPoopie]

Z400? what happened to it? i just got a kfx400 which is the same thing 2004 i havent really riden it much cause it needs some work but are they any good?

Thanks,
Clayton

[85ytz250n]

The Z400 is much faster stock than the 400EX. I have read alot of articles that say the Z450/400 is the most race ready quad you can buy. My buddy wrecked his and bent the frame, the new one doesnt have a VIN. I couldnt find the one on my EX so I was worried that it had been totaled out to, I found it though.

Barry

[Groundworx]

Putting a higher compression piston in it will make a huge difference. I have an 11:1 in mine on the stock bore. It also has all the bolt ons (pipe, jet kit, K&N, rev box) and it will woop up on a stock one. That piston made a huge difference and was installed when the bike only had about 20 hours on it in 2001. Never had a problem since. I think 3600 is a prett good price. I am not sure though that the LTZ400/KFX400 are a lot faster than the Honda 400EX in stock form. I have heard from numerous ATV dealers that they have more top end, but the rest is pretty much the same. I have never ridden one of the other 400s though so I have no personal experience. I have a full White Bros. exhaust on mine and I agree about the sound. Mine is loud as hell and the piston made it even louder. It is cool if you are showing off, but I mianly ride around with my kids. When I am trying to just hang out and put around with them, the noise gets annoying. You will be happy with the Honda though, they are great quads.

[85ytz250n]

My first mod is going to be a larger than stock oil cooler, bigger is better and cooler is better. I rode it over the weekend on a creek around my house that has a lot of sand, I was impressed to say the least. Prior to this the only thing I have ridden in the sand is the bigbear 350 2x4, the difference is black and white. The power was there real low and it was light enought to carve the faces without flipping and I hit a couple decent jumps, never bottomed out even though i am a large guy. I cant wait to get a little more seat time and really push its limits in stock form before I start bumping it up a step.

Barry

[hoser]

I have a 99 400EX, I seen a pipe shootout where they tested like 17 pipes the BEST pipe only made 2 - 3 hp more than stock, I want to see what a modified stock pipe would do, Honda did their home work, some of the pipes like the double barrel made 1 hp less than stock lol, YES they rejetted after changing each pipe....

Remove your head pipe and look into the end where they welded on the flange that bolts to the head, the weld that connects the flange to the pipe sometimes is too big and sticks out into the flow path of the pipe, take a die grinder or a file and smooth it down be careful not to thin it out too much just take the hump off, this was good for 1-2 hp on the XR400

Get your jetting spot on, the air box could stand to be opended up but for what little you gain you expose your filter to the elements that will kill it quick.

I have rode with guys that spent big bux on parts, carb, cam, pipe, jet kit, K&N, air box mods, in the end they were ---> <------- that much faster than my stock 400EX the 400EX's I seen that pulled away from me strong were all the big bores 440cc kits, 500.00 carb, 400.00 porting etc.

I forget the honda part number but the "no rev" cdi they sell for 100 bux is just a cdi from another Honda application I think its off a XR200 ? and is only like 55 bux, down side is it donr come with really cool stickers, I will see if I can find the Honda number, after seeing how much good the 100.00 CDI mod did for my buddies 400EX ---> <--- I never bought one.