440 questions

[bigbad400]

do they make a special jet kit for the 440 kit? and my plan is to install the 11:1 440 kit with stage 2 cam, stage 3 amr coil and cdi combo kit, and the crf 450 timing chain.
is there anything else i need to know about this stuff befor jumping into it? i plan to do all the work myself.


and the reason i ask about the jet kit is that all the ones ive seen say for use with airbox mods and a pipe, i already got that done, and i only jetted up to a 42 pilot and she runs awsome. thats alot of upgrades to be using the same jet kit, so im thinking im gonna need bigger jets, should i buy individual ones or do they sell a 440 jet kit someware?

[xtullyx16]

DUDE.. are u serious? i dont mean this in any flaming way but how could they make a jet kit just for a 440? they would have to know exactly what mods u have and what elevation u are at haha.. just got buy sum jets seperately

[bigbad400]

you smart *** type in any quad you can think of and youll find a jet kit, you can buy them for stock blasters and they also have a 240 kit it just moved it all up to bigger jets. they kinda do know if all you do is add the 440 kit to you quad they got a good idea. how do they know what to sell for a slightly modded machine, and not know for a more modded machine.

you wanna be a dick when someone askes for help, then fine. but im in it for the fun just like you buddy. im not flamming or trying to be smart dude, i just wanted to see if i could save the hassle playing the guessing game with jets.

[400exrider707]

Relax its ok!

To answer your question they probably make them, but IMO are nonsense. All a jet kit is, is a bag of multiple jets that they're making a killing on. Just because they give you a bag of jets doesn't mean the correct one is even in there.

Not always does a larger motor need larger jets. There is a vacuum pulse on the carb coming from the motor. As the piston goes down in the cylinder its literally sucking fuel and air right from the carb. If you have a motor that is on its last leg, its probably got a relatively weak vacuum pulse and wont pull as much fuel. This isn't always how it works, but just something to think about. I've seen 450R's with 520 big bores running a 150 main jet VS a piped and filtered stock 450R using a 185 main. It's because the 520 had a wicked vacuum pulse on the carb and pulled more fuel through a smaller hole than the piped 450R did on a larger hole. The hole size is the restrictor of the fuel, but the motor is what determines how much is pulled through that hole. Does that make sense?

When building a solid 440 I would always build it reliable first. IMO a 440 should have the GT Thunder heavy duty head studs (unless you like blowing head gaskets) and a heavy duty rod. 11:1 compression you can probably get away using the stock rod, but I would still invest in the head studs.

As far as your jetting goes, we can give you recommended jets to buy (much cheaper) if you tell us what mods you're using with this, and then you can test and tune from there. This will also teach you how to properly jet a quad instead of buying a "kit" and just throwing in whatever some dude in a cubicle typed up on the jet kit instructions and has probably never touched a quad thinks.

[bigbad400]

they probably are nonsence now that you put it that way, but it was a simple logical question, do people always make fun of less educated guys that just want a bad *** quad and to save some time? seems rude.

but i was once told- arguing on the internet is like running in the special olympics, even if you win your still retarded!!!!

you seem to know alot about these quads, so why would it be smart to get new head studs, i dont see how a bolt could make you blow the gasket. i understand the coment about the rod and i already had planned to get a heavy duty rod.
thanks alot for the help, and thanks for being honest.

dan

[400exrider707]

Originally posted by bigbad400
they probably are nonsence now that you put it that way, but it was a simple logical question, do people always make fun of less educated guys that just want a bad *** quad and to save some time? seems rude.

but i was once told- arguing on the internet is like running in the special olympics, even if you win your still retarded!!!!

you seem to know alot about these quads, so why would it be smart to get new head studs, i dont see how a bolt could make you blow the gasket. i understand the coment about the rod and i already had planned to get a heavy duty rod.
thanks alot for the help, and thanks for being honest.

dan

It's atvirders.com There are a lot of kids on here. There will always be arguing and nonsense. Best bet is to just ignore it. Also like you said it's the internet so sometimes it's difficult to understand what someone is trying to relay. Try not to take things too seriously and things will go smooth.

400ex is notorious for stretched/pulled headstuds. The studs hold the head to the cylinder so if they stretch or pull, then there is a leak at the headgasket. Quite common problem actually. What happens is when guys start putting in high compression pistons (say 11:1 and higher) you start generating more heat in the motor. The heat actually breaks down the aluminum of the cylinder and then the studs can pull out of the cylinder due to the pressure inside the combustion chamber. This is made worse with thin cylinder sleeves (guys who bore out to 426, which is the largest bore on the stock sleeve). This is fixed with the heavy duty studs. The studs are oversized and have a much better hold in the cylinder. Also a roll form tap is used for the threads in the cylinder and this is much stronger than a standard cutting tap. (If you have GT Thunder install them anyways)

Being you're only doing an 11:1 build it may not be an issue. It might though. All these problems are made worse when you jump to a 440.

Why are you going to a 440 anyways, and what are your current mods?

A lot of guys actually end up going to a 416 VS. the 440 once they figure out everythign involved and realize the power VS. reliability. A well built 416 can RIP! I've seen 416's eat 440's alive. It all depends what you want to do with this quad and where you see it going.

[bigbad400]

well i dont really have racing plans or anything like that i just want a really rippin fast quad to go play in the dunes and on the local track and of course the back 80.

mods now are a cheap dg pipe that sucks. (never again will i buy a dg pipe)
a k&n filter, outerweres, no lid, snorkle and whatnot.
choke removed, 42 pilot.
thats it besides tires and nerfs and that.

i just got the quad a couple months ago and it only had the filter on it. but i bean riding since i was 6 and im 21, lots of different bikes quads and trucks, and now im ready to build a good fast quad that will show up all my buddies and make the one with the new ds 650 cry when i fly by him. (i almost do now!!!)

so i bean saving my money for a good build. i paid a great price on the quad. and i think i found one that i actually like everything about how its set up. i did up a blaster to the till and i couldnt ride it without breaking it. and i dont like yammies to much anyhow.

im open to your suggestions on the 416 build, but im not dumb so dont be affraid to get technical. tell me why you think this or that may better suit me. im not doing suspention thow. just the motor work for now. im only 135lbs so the stock ride is pretty good and i like how it feels for me.

i really appreciate this help, i was kinda headed blind into this and was really looking for someone to help walk me through a good solid ripping fast build.
ps i will be going to a hmf or motoworks or something maybe even a yoshi. so thats covered.

[400exrider707]

Well since you're not racing, suspension may not be AS important, but usually that is where you start. If you're busting down the trails and you can hold your throttle on longer because your suspension is soaking everythign up, and those big bad faster quads have to let off because they're getting bucked everywhere, you're going to win on a slower machine. Suspension although expensive is one of the most important areas on the quad. I'm going to leave it at that, since this is the powertrain section.

A well built 416 would be a good start in my opinion. If you truly want to go 440 and have a fire breathing monster, you need to be prepared to spend some money.

I have a couple more key questions before I can point you in a direction of build here.

Would you want to run pump gas or are you ok with running race gas? (usually cost driven)

How much are you looking to spend total, and are you doing this all in one shot?

[xtullyx16]

bigbad400 .. u took it the wrong way man.. ur better off buying jets seperatly then buying a big bundle of them.. but anyways man why not go between the 440 and 416? get a 426.. its got gobs of torque for trails and it also revs faster than a 440.. i would suggest also putting a crf450 timing chain.. heavy duty headstuds.. sleeve it if u want..no need for a heavy duty rod then.. but whatever u choose it should rip.. i just built a 426ex and after i jet it accordingly it should really rip

[bigbad400]

well dude i totally get what your saying about the 426 but thats pushing the motor a little far without upgrading the rod and all that just like i was told to do with the 440. i like the idea of a 416 and the reliability issues i was talked to about makes me believe in the long run, ill still be way faster. im thinking ill save some money and get good suspention, and listen to a few more suggestions on the 416.

i would like to stick with pump gas, even if its premium its still cheaper than race gas.

i got the money there guy not a problem, all in one shot, planning to have a good winter project.

(also doing up a stock banshee with pink frame and pink chrome rims and black plastic. with all the shiny **** the girlfriend wants. no motor mods or even a pipe, just looking pretty this year.)

[jedneck]

If you dicide on going With a 440, I have a cylinder and piston I'll sell you. the piston is a wiseco 11:1 new in the box. The cylinder is going to need a bore to fit the piston (It was a 435). Let me know if you want it. $200 shipped.

[bigbad400]

you can buy a 440, 11:1 piston kit with a stage 2 cam, and do the work yourself and you wont spend 300, you can buy the piston alone like you got for 124 shipped to my door, now why would i need a cylender? didnt your machine come with one stock? couldnt i bore that one, mine came with a cylender, man honda must have ripped you off bro. no thanks on the parts, prices are real steep and like seriously, why would i need 2 cylenders?

[cdale2002]

Originally posted by bigbad400
you can buy a 440, 11:1 piston kit with a stage 2 cam, and do the work yourself and you wont spend 300, you can buy the piston alone like you got for 124 shipped to my door, now why would i need a cylender? didnt your machine come with one stock? couldnt i bore that one, mine came with a cylender, man honda must have ripped you off bro. no thanks on the parts, prices are real steep and like seriously, why would i need 2 cylenders?

A 440 kit will cost more that 300.00 is because the 440 kits have a larger sleeve than stock so the cylinder itself has to be bored out just so the sleeve will fit. Then you have to get the sleeve installed then and possibly bored to fit the piston. Remember that the problem with the 440 kits is that you will not be able to install a stock size sleeve without replacing the cylinder as well. Also just don't push off the thought of installing the oversized studs because it will more than likely pull them out and blow the head gasket with a 440 kit installed (will more than likely go at the point you don't want it to). And for the couple extra bucks install a crf450r timing chain for any one you chose to do. Take it for what its worth and just do it all at once and you'll have the peice of mind that it was done right.

Edit: Another important thing alot of people over look in an engine build is head porting which can make or break power (if you don't do it) good gains

[400exrider707]

I'm not sure if you need/want a 440 fire breathing monster or not, but if you want something like that I would build:

11:1 piston (your choice of brand, CP is one of my favorites)
Stage 3 hotcam
Port and Polish with oversized valves (make sure piston valve reliefs fit to the valves)
FCR 39mm carb
Full exhaust
CRF 450 cam chain
GT Thunder heavy duty head studs
Heavy duty rod (not a necessity on 11:1, but still a good idea)
Probably need a new clutch and put some stiffer clutch springs in.
Your 440 will need a new sleeve, then your stock cylinder will need to be bored to accept the new sleeve, then the sleeve bored accordingly to the piston.


I like your other idea better, invest in some suspension and do a mild 416 build.

11:1 416 piston (again your choice)
Your choice of cam (I used a stage 1 hotcam, any of the hotcams are usually the most practical when it comes to cost and effectiveness)
Maybe a trail friendly port and polish
Full exhaust
CRF450 cam chain.

A 416 with a cam and a mild port and polish will still run awesome.

It will be that much better with proper suspension to put the power to the ground.

[bigbad400]

that 416 sounds like the way for me to go. it leaves alot for improvement should i get the itch. it sounds like a beast if done right, and its gonna allow me to do suspension work as well.


i really appreciate the time and thaught you put in to help me out on my decision.

[400exrider707]

Originally posted by bigbad400
that 416 sounds like the way for me to go. it leaves alot for improvement should i get the itch. it sounds like a beast if done right, and its gonna allow me to do suspension work as well.


i really appreciate the time and thaught you put in to help me out on my decision.

No problem, thats what this site is for. This is the only thing I come back for, I'm glad there are still people out there who are genuinely interested in getting information and correct information at that. Good luck with your build and be sure to post pics and write ups of your progress!