PDA

View Full Version : 400ex extensive upgrades



chayes627
01-09-2008, 11:49 AM
Here’s my list of mods that I am going to put on my 2007 400ex let me know what you think and any suggestions.

Suspension – Elka triple rate sport & racing front shocks w/ piggyback reserviors
Elka dual rate sport & racing rear shock w/ remote reservoir

Engine – Head Port and polished
Hot Cams stage 2 cam
Titanium valve springs
Hardfaced rockers
Ice cube/max power 440 bore cylinder
Hot Rods stroker crankshaft and double forged rod (460cc)
K&N replacement filter
K&N Xtreme power lid
Procircuit T-4 slip-on
Stock head pipe for throttle response
Extensive carb tuning
FST secondary oil cooler
Heavy duty clutch springs

04TRX400EX
01-09-2008, 01:36 PM
Not a bad plan by any means. The only thing I would change would be the Pro Circuit exhaust ... it's not the best choice. For what you are doing, look into a Sparks or even a HMF.

My question is why go immediately to the 460 stroker kit? For the most part, 400EX owners will progress through bores as needed, going from a 400 to 416 to 426 to 440 and then maybe a 460.

As for the Elka's, be sure to be very honest with whoever is taking the build specs for them. Your weight, tire size, riding style, etc. plays a huge role in the setup. Elka doesn't seem to have the best valving from the factory as it is so make sure to provide correct info so it will at least be close.

chayes627
01-09-2008, 02:03 PM
i'll look into the exhaust. one of the reasons i picked the exhaust because on my friends bike it helped with throttle response. also i really like the deep throaty sound that it produces. as for the 460 kit I do alot of trail and mountain riding and i prefer alot of torque and low end to mid range power which is nice in the conditions i ride.

01-09-2008, 02:53 PM
Originally posted by chayes627
i'll look into the exhaust. one of the reasons i picked the exhaust because on my friends bike it helped with throttle response. also i really like the deep throaty sound that it produces. as for the 460 kit I do alot of trail and mountain riding and i prefer alot of torque and low end to mid range power which is nice in the conditions i ride.

get a HMF or Sparks and it wil maximize yoiur gains with those mods. I also disagree on the shocks, i think there are way better and even cheaper alternatives to Elka. The K&N power lid isnt worth it either IMO, it will restrict flow over a open air box lid and will set you back $100. If you want the protection of no air box lid with all the same flow get a Outerwears air box cover $19. And with the hardfaced stuff I think thats only for WebCams not Hotcam. With hardfaced stuff I think it will eat up your hot cam.

RATPACK Z400
01-10-2008, 02:02 PM
The money you spend doing that to that 400ex you could get a 450 .

Honda#4
01-10-2008, 02:25 PM
Gonna be pretty hard to move a quad without A-arms, what have you decided on them? Whats your budget?

400exMO
01-10-2008, 06:42 PM
FoxHondaRider tell me your experience with elka and with other shocks? Elka makes a good shock and has good customer service. Their valving might be alittle bad at times. But most people who say that are not able to setup their suspension correctly, so they blame someone else.
Do not get the hardened rockers with a hot cam, it will eat you cam. You will need a hardwelded cam to accompany those rockers.
As for exhaust I would look into a Sparks x-6 or HMF full system. They will maximize your hp.
You should also get HD head studs, GT Thunder.
Hope this helps.

chayes627
01-14-2008, 06:09 AM
the reason im not going with wider a-arms and axle because i mostly do trail riding and dont want to ahve any problems with that. so i figure if i get the thing lowered down with the elka's ill be able to get to stick better

GPracer2500
01-14-2008, 12:47 PM
Why titanium valve springs? Did you mean titanium valve spring retainers?

Why the hardfaced rockers? As mentioned, make sure the rockers and the cam are the same "hardness".

There is no Ice Cube cylinder for the 400EX. I'm sure Max Power will be happy to re-sleeve you stock cylinder though.

All that and no carb upgrade?

What piston?

400exMO
01-14-2008, 02:31 PM
maxpower does make a cylinder, their website still sells one.

GPracer2500
01-14-2008, 03:01 PM
Do they? I looked and didn't see it. They show a fuzzy picture of a Duncan PC4000 cylinder on their website. But that's not an Ice Cube cylinder. I think all their 400EX work utilizes OEM cylinders, hence the "stealth" designation on their 400EX kits.

The show that picture but make no mention of any aftermarket 400EX cylinder. They mention re-sleeving, sending in your cylinder to save $350 on the stroker kit (a new OEM cylinder retails for about $350), they say nothing about an aftermarket 400EX cylinder, and Duncan wants almost $1000 for the PC4000 cylinder alone. To me, that all adds up to: no aftermarket 400EX cylinder from MaxPower, just re-worked OEM cylinders. Which is fine, I wouldn't personally spend a grand on a PC4000 anyway.

I think they're just using a picture of a PC4000 so they can show a cylinder.

chayes627
01-15-2008, 06:15 AM
looking back at the emails between the rep and i i think you might be right cause i asked about a kit with a new cyclinder and he said yeah we have a kit when do you want the work done? we'll need your engine shipped. looking back at that he never said anything about the new cylinder. well that kinda changes everything cause the whole reason i was gonna go for the 460 stroker was getting a new cylinder so i was going to make everything right. with that i might be back to my original plan with a 426 kit but no cyclinder or crank, no hardfacing of the rockers or titanium valve spring retainers. But i'll still go with the rest of the stuff except maybe go with a stage 1 hotcams for extra low end.

TheNewn
01-15-2008, 11:43 AM
To me that seems like it'll be too much motor for just the stock chassis with Elka's. This is what i would do for good performance on the cheapish side for the motor.

11:1 comp pistion (could go stock bore, or 406/416/426, whichever you prefer)

Hot cams Stage 2

HD valve springs

HMF Full system exhaust

K&N Filter or similar, no air box lid with an outer wares over the box and the filter.

MAYBE a port/polish but probably not till the first or second rebuild. I'd probably go 450R carb before i did port/polish. maybe.

You can get that stuff pretty cheap, and after those mods were done, i'd seriously look into some more stuff for that chassis. Full shocks, steering stabilizer, Axle/Arms, Antivibe stem with maybe Flex bars, Nerfs, Hipers.

Things like that. I think you're probably focusing on the wrong aspect of the quad

RATPACK Z400
01-15-2008, 05:15 PM
When you bought your 400ex did you know at the time of purchase that you were going to do this to the quad? and If you did why not just buy a 450 and have more hps and have relieablity with those mods that quads going to be so unrelieable and so expensive to do .you were better off buying a 450r.javascript:smilie(':confused:')

RATPACK Z400
01-15-2008, 05:15 PM
When you bought your 400ex did you know at the time of purchase that you were going to do this to the quad? and If you did why not just buy a 450 and have more hps and have relieablity with those mods that quads going to be so unrelieable and so expensive to do .you were better off buying a 450r.javascript:smilie(':confused:')

TheNewn
01-15-2008, 09:30 PM
Perhaps he got a great deal on the 400EX? Maybe he's a trail rider and values Reverse.

Who cares? If its what he wants, let it go.

chayes627
01-16-2008, 06:45 AM
thats true i did get a good deal $5200 brand new. and the reverse is like a must i use it alot. not to mention i have put that thing through some stuff including mud which reverse comes in handy alot. i have pro armor nerfs, main skid pan, swing arm skid, and ebc brake pads. i'm actually getting ready to order pro taper 7/8" bars atv mid bend and roll design +1/2" steering stem. here's a pic as of about a month or so ago

TheNewn
01-16-2008, 09:47 AM
Just a little something to think about, If it were me spending that kind of money. I'd get Flex Bars and a cheaper steering stem, Roll Design things seem to be overpriced?

I think you'd be happier with Flex bars and a different steering stem. And the price would probably be similar.

chayes627
01-16-2008, 11:00 AM
you think so? what brand would you go with for the steering stem? ive heard nothing but good things about the roll design except the price. as for the bars i havent really heard anything about flex bars

Honda#4
01-16-2008, 01:53 PM
Price is the only thing that comes to mind when you talk about Roll Design. I have the stem and it's great I really dont care about price to much but havein a $400+ stem on a quad would tell a person to look else where for a stem.

If you want another choice Houser makes a great stem also.

TheNewn
01-16-2008, 06:51 PM
Anyone that has Flex bars loves them from what i've read. Apparently they're worth every penny.

Just about every after market stem is going to be stronger than stock. I'd find the best deal i could. I'd also go with +1 or even +2.

here's one that i had in mind

Burgard:

http://www.burgardcycle.com/xcart/product.php?productid=4&cat=1&page=1

200 bucks, great deal on a stem i'd say.

That and flex bars is what i think you should get. Just do your research and learn as much as you can. Go ahead and look up Flex bars on the forum and read what people have to say about them.

chayes627
01-18-2008, 07:45 PM
yeah i see the prices of their parts but i always hear good things about them. and those bars look really nice i actually think i might get a pair of those. thanks for all the input