Best 400 Kit!!!

[ATV_MAN]

I have a 2001 400ex with dmc pipe and k&n filter. I am looking for a really good mod kit that will not only add power but last long.I mainly ride in the woods and trails and race every now and then. I would like to know what everyone thinkls is the best bore kit . 416,426,440 ........etc .I am trying to spend least as possible and get the most out of it. Please tell me what you think is the best , how much it costs, and where you can get it. Thanks in advance.

[RED121572]

Ive heard nothing but good things about the 416 kit. If I had to do it all over again...and I will next winter, i wouldve gone with a 416 kit. With that, Im gonna use a 13:1 piston as well.

So, from what I understand, the 416 is the way to go.

Good luck with that motor hoss!!

Well my 400 is getting a 440 national motor in it as we speak. Its gonna cost about $2500. Does that help?

[RED121572]

When you get some handle bar time on top of the 440 National kit, let us know how she does!!:eek:

[ATV_MAN]

Yea I would like to know how it goes. I dont think I am going to be spending nearly that much, I'm shooting for somewhere around $500 finished.

[ATV_MAN]

Hey red,

You think if I went with the JE 416 kit from marcums, and get the xr400 cam, I would have to do anymore upgrades? I heard that stuff is good so far, but it is supposed to wear down the stock parts. Thanks

[Dave400ex]

If you Trail Ride/Race I would Call TC. He has a Motor Setup for Riding in the Woods and it is suppose to be Fast. Plus it`s Cheap.

[K_Fulk]

A lot of the lengevitity depends on the compression. You have to keep an eye on anything over 11:1

[4punksdad]

I got a chance to put a little seat time on a 440. The bike had a 15T front sprocket, and 22" rear tires. I thought it was very lacking in the low end dept. but it had some nice pull in the mid range. I am not sure how much this particular 440 kit costs, but I wasn't very impressed. JMHO

[Tommy 17]

4punk if u get a chance to ride the bike again put a set of 20s or a 14t sproket on it and ur whole story will change about the machine...

[4punksdad]

Originally posted by 400ex21
4punk if u get a chance to ride the bike again put a set of 20s or a 14t sproket on it and ur whole story will change about the machine...

I am sure you are right. Thats why I took time to point out the gearing set up. I would like to try it again if he ever makes those changes.

[Andrew400ex]

hey im also interested in gettin a 416..i think marcums can do everything for like $200,right? is that any good? i know it includes parts,choice of cam,return shipping and boring of the cylinder. and kind of a random question,but what is "port and polishing"? thanks a lot guys.

-andrew

[ATV_MAN]

Andrew I think I might go with this kit also. Have you contacted marcums yet? I am going to call them tommorrow. Thanks

[Andrew400ex]

yea thats cool..the price seems awesome! when u get it let me know how ya like it!

[RideRed04]

The 416 kit (piston, boring, gaskets) is $165. I am pretty sure that inclues the machine work, but I wouldnt bet my life on that. The cam just went up $15 to $135 to your door, still an excelent price. Compare that to the price of a slip on silencer, and you will see how good it is.

[ATV_MAN]

I think I am just gonna have the 416 and machine done, and the xr400 cam. But im still not sure if i should upgrade anything else???

atv man dont get the xr cam. For a 10 dollars more you could gets gt tunders drop in cam.

[Zero Z400]

I wouldn't get the XR cam. 4punks, did the 440 just have the 440 and piston? If it did that why you won't be 2 impressed. I thnk with any engine kit you need to go all the way to get a good outcome. I would get the Marcum's416 and a FCR 39mm carb. Then later you should get a port and polish from TC.


Later

I would tell you to go with the 426, use a JE 13 to 1 piston and a XR 400 cam. I believe the cam is like $90 and the piston is $165. You'll have to run race gas but that piston is actually 13.5 to 1. Scince you ride in the woods you want alot of torque and that high copression will give it to you. A 416 kit gives great mid to top power but you want bottom end torque for woods riding. I would go with the 426. It rips in torque and the compression doesn't hurt anything. Ive had mine for better than A year and haven't had any problems. I did just put new rings in it though but thats maintenance. Call Mike Kinkaid at For Dirt Only before you do anything and price it out cuase I might bve a little high on prices but not sure. A guy who had the 426 Je piston with the stock cam dynoed at 39 horse power from FDO. I don't think a 416 will give you that. Call Mike at 740-967-1078, call after 6 pm eastern time or on the weekend. Later

[Zero Z400]

the 426 won't get u that much more bottom end then the 416. The 416 doesn't just improve mid-top. It improves everywhere. The 426 does have a little more power everwhere but not much. And for the price the 416 is hard to beat. I think the downfall of some engines is in the porting. Porting is a big factor in hp and in the powerband. I would get the 13:1 piston cuz u have to run race gas. 11:1 is fine but an oil cooler will help,


Later

[deansfastway]

There is much power to be found in the cyl head , We flow port the bowls and perform a 5 angle valve job, bore the cyl 87/88mm ,install either a WB 1498 or an XR 440 HRC cam and cryotherm the rockers and clutch assy. Oh yeah youll need at least HD clutch springs in any hopped TRX motor so it doesnt slip. Edelbrock or Keihin FCR carbs are a good addition as well as a PRO CIRCUIT T-4 slip on . FASTWAY MOTOSPORTS (New Jersey)

[deansfastway]

Dont go too high on that comp ratio , also when you bore it out to 425 the sleeve gets real thin . 416 makes real good power.

[4punksdad]

Originally posted by zero
I wouldn't get the XR cam. 4punks, did the 440 just have the 440 and piston? If it did that why you won't be 2 impressed. I thnk with any engine kit you need to go all the way to get a good outcome. I would get the Marcum's416 and a FCR 39mm carb. Then later you should get a port and polish from TC.


Later

I am not that knowledgable on the 440 subject. The guy is a member of this board. his username is 2-balls or something like that. hey victor, are you out there????

anyway, he had an aftermarket carb........not sure what kind. he has some trick suspension & chassis mods too. its a nice 400, just didn't seem worth the extra money to me.

[Andrew400ex]

hey,quick ?..what is porting and polishing? is it any different from boring? im pretty sure i know what the polishing part is,but what about the porting?:huh

[ATV_MAN]

You guys have a lot of different set ups, but I still think I might go ahead with the 416 kit. Still not sure about the cam though, I might check into them a little more. Does anyone know the number for For Dirt Only? Are they in ohio? I might give them a call if they are instead of marcums beacause they are closer, and I have heard good things about them also. If anyone has this kit from there, or anymore suggestions feel free to post them.

[400ex99]

im ordering a 416 kit from marcums, JE piston 10.8:1 and a WB track cam #1498 and Terry is going to port and polish the head.
from what i hear: the papers from the WB cam says that i dont need better valve springs, i can use the stock ones, but Terry recommends titanium springs. is this because he's doing the port and polish? whats your opinion on this? better springs or stock

[MIKE400EX]

The springs are steel, the RETAINERS are replaced with titanium ones. They're lighter than steel so effectively it's like having a stiffer spring w/o the extra pressure on the cam (or other parts).

[Andrew400ex]

and i still dont know what port and polishing is.....and how much is terry going to do this for u?

[ChadEXer]

Whatever terry says i would go with!!!
As far as the motor kits I would reccomend the 416 also! this might make a few people mad but I think the 440 kit is a waste of money,,the 416 I had in my bike was pulling on every 440 I raced! And for some reason TC told me he builds about 8 416's and 425's to every 440! There has to be a reason for that!
I dont understand why someone would send $2500 to Duncan(Im assuming thats the 440 national kit he was talking about) when you could get a 505 from TC for the same price,,If you wanted a 440, why not send TC half that and get a better motor! Im not bashing Duncan because they do have a nice history, but TC's history is quite a bit better and he is cheaper!!!

[ChadEXer]

Originally posted by Andrew400ex
and i still dont know what port and polishing is.....and how much is terry going to do this for u? Im not sure how much terry charges for it but if your going to do the motor kit you definately need to get it ported\polished. What they do is grind out the exhaust and intake ports to make them larger then they polish them for a smooth flow. On a built motor port\polish work is very important,,,thats what sets some of the engine builders apart!!!
thats why you can see a 250R with a true 250cc motor spank a R with a 370 kit in it!!!

[Andrew400ex]

chad did u ever get ur 505 back from TC yet? i mean it's been months now,right? and can u please tell me what port and polishing is?thanks