440 Build, would like suggestions on vavles, carb, etc

[Xplorer99]

hey guys, well right after i got the 400 tore apart i had to dump money into my truck, then my grizzly needed u-joints so im just now starting to buy parts for my 440 build.

So far; i got a new wiring harness, replaced the headlight switch so that fixed the short that i had. going to order tie rods/ends and all the brake pads today from ebay.

as for the motor parts im taking the suggestions from a few people on here and just watching ebay, i found its alot cheaper! im getting the new 440 cylinder, Wiseco 11:1 piston. Stage 2 Hotcam. my local atv repair shop just got ahold of GT Thunder and became a dealer so they can get my the GTT headstuds cheaper and install them. im getting the head Port and Polished.

what kind of valves should i get? i figured i might as well upgrade them since i have it apart.

also what would be advantages of the 450R Carb and the Edlebrock carb?

thanks for the input!

[steve181]

Ive always loved my fcr 39mm carb

[Xplorer99]

oh ya, suggestions on clutch parts too, im not sure what kind is in it, its really stiff tho so i think its got heavier springs in it at the least...

[Xplorer99]

btt for suggestions on valves, going to send my head in to get the work done next week! cant wait to get it back together

[Xplorer99]

UPDATE: thanks for helping me with all my questions from previous threads, after some much needed over time at work i bought ALOT of stuff.

right now i got a NEW 440 cylinder from ebay with naruma sleeve, 11:1 Wiseco piston, GT Thunder Head studs. Stage 2 Hotcam...and on the way i have Kibble White black diamnond intake/exhaust valves, and new valve springs. after they get here the head and valve cover is going to BCS Performance to get Cerdi valve job, Port and polish the head and install the valves and springs.

Anyone have thoughts on GT Thunders HD timing chain?

planning on putting in whole new Hinson clutch after i get the motor broke in...


the last thing im looking at is getting an 04/05 450R Carb. see them on ebay rather cheap. i think i read somewhere i need an adaptor and need to mod the carb? i just read a post that said they fit right one. any help with that?

cant wait to get this beast running!!!

[flyboy1294]

Originally posted by Xplorer99
UPDATE: thanks for helping me with all my questions from previous threads, after some much needed over time at work i bought ALOT of stuff.

right now i got a NEW 440 cylinder from ebay with naruma sleeve, 11:1 Wiseco piston, GT Thunder Head studs. Stage 2 Hotcam...and on the way i have Kibble White black diamnond intake/exhaust valves, and new valve springs. after they get here the head and valve cover is going to BCS Performance to get Cerdi valve job, Port and polish the head and install the valves and springs.

Anyone have thoughts on GT Thunders HD timing chain?

planning on putting in whole new Hinson clutch after i get the motor broke in...


the last thing im looking at is getting an 04/05 450R Carb. see them on ebay rather cheap. i think i read somewhere i need an adaptor and need to mod the carb? i just read a post that said they fit right one. any help with that?

cant wait to get this beast running!!!

Where the valves you purchased over sized?

Don't get the GT Thunder HD timing chain: get the CRF 450 timing chain. It's half the price and basically the same thing.

Also, unless you are planning on doing drag racing, the 04/05 450r carb is a little bit bigger than you really need. While it is an improvement from stock, if you were willing to dish out the money to get a 39mm FCR, you could unlock a lot more of the bikes potiential.

[Xplorer99]

Originally posted by flyboy1294
Where the valves you purchased over sized?

Don't get the GT Thunder HD timing chain: get the CRF 450 timing chain. It's half the price and basically the same thing.

Also, unless you are planning on doing drag racing, the 04/05 450r carb is a little bit bigger than you really need. While it is an improvement from stock, if you were willing to dish out the money to get a 39mm FCR, you could unlock a lot more of the bikes potiential.

ok ill look into the CRF450 timing chain

i bought the standard sized valves....im guessing after a valve job i need over sized dont i ???

i dont race with it, but i want to be able to keep up with my friends, they all have 450R's and stuff. i seen a 450R carb for 50 bucks on ebay, actually a few of them between 50 and 100 bucks. so be its rather cheap, wouldnt it still be worth it to put it on? i read alot of good things about em....

thanks for the input!

[bens250ex]

just get the 450 carb cheap and works great

[Xplorer99]

Originally posted by bens250ex
just get the 450 carb cheap and works great

do i need to modify it at all? i read i need an adaptor or something, it was a while ago so i cant remember. it has to be 04-05 right?

thanks! im going to buy one on ebay tonight

[bens250ex]

yes 04 to 05 i had to cut out some of the inside of the intake boot but someone did make an adapter.

[Xplorer99]

Originally posted by bens250ex
yes 04 to 05 i had to cut out some of the inside of the intake boot but someone did make an adapter.

o ok, so like a 5 minute mod, nothing special then, ill be getting one then. any thoughts on the valves i got? should i got the oversized ones?

[jcs003]

go with a lectron carb. it takes about 5 minutes to tune one and the performance gains are well worth it. i bought one for my 250r. loved it then went and bought another for my hybrid. money well spent.

[flyboy1294]

Originally posted by Xplorer99
o ok, so like a 5 minute mod, nothing special then, ill be getting one then. any thoughts on the valves i got? should i got the oversized ones?

No man don't worry about the valves. Some more performance can be had if you go with oversized, but the stock size works just as well. You can use them no problem. And they can still do the valves job, they will actually probably charge you a little less.

And the adapter people were talking about is ZrPilot's. He used to custom machine them for people. They made the carb almost a bolt on. Normally, you have to shave the inside of the intake boot and do a lot of stretching. Then you have to move the airbox about an inch forward (none of this is really hard, it's just inconvienient) I think he still makes them, but he only does them in orders of 10. You might want to contact him and see if he is planning on making an new batches.

* The 450r carb can be had for about $100 used on eBay. ZrPilot charges $47 for his adapter. If you look hard enough you can find a 39mm FCR on eBay used for $150+/- It's only a little more money, and you don't have to worry about all the stretching airboots and plugging hotstarts. AND it will deliever most of a forced intake a lower RPM. Just something to think about if you haven't made up your mind totally.

[Xplorer99]

ok well my valves/springs are going to be here today. im bidding on a 450R carb on ebay. ill pry just mod the air boot myself.

[05dmax400ex]

Not trying to hi-jack the thread just didnt want to start a new thread for this question, is the fcr carb the off a yamaha? I did a search on ebay and found ones that came off a yfz and raptor, is thisthe right one?

[bens250ex]

^^^^ not sure about that, but i didn't have to move the airbox forwards i don't think. but if i did it took about 2 secs cause i don't remember even doing it.

[Xplorer99]

i couldnt find an FCR carb for a 400ex either... but im going with the 450R carb anyway.

[flyboy1294]

Originally posted by bens250ex
^^^^ not sure about that, but i didn't have to move the airbox forwards i don't think. but if i did it took about 2 secs cause i don't remember even doing it.

I have heard several people talk about moving the airbox forward like an inch to compensate for stretching the boot around the bigger intake and pushing it further on. However I have never tried this, so maybe it can be avoided.

05dmax400ex:
They do not make an FCR carb specifically for the 400ex. If they did, it would be much smaller than 39mm. The closest thing I can think of is the Edlebrock 440 carb (which is rather unpopular) I have seen a lot of people use the YFZ450 carb on their EX's. That is what I'm in the market for right now actually, it's 39mm and works very well in this application. The only FCR carb that I have heard of people having issues with is the 40mm FCR for the CRF bikes, and this is simply because it's too tall to fit underneath the gas tank.

[odog]

fcr carb from curtis sparks works great its an upgrade thats defiently worth it.no modifications is needed and it also comes with a new throttle cable. but it does cost alot.i went with the kibble white valves my intake is oversized and my exhaust is stock i dont know how much performance difference it is because i had so much work done at the same time but most people told me its good for about 1/2hp gain.

[jcs003]

go lectron. tuning is just the turning of a tool. so easy a caveman can do it. no taking the carb apart. just remove three screws, pull out the slide and turn the metering rod, in or out.

[bens250ex]

Originally posted by odog
fcr carb from curtis sparks works great its an upgrade thats defiently worth it.no modifications is needed and it also comes with a new throttle cable. but it does cost alot.i went with the kibble white valves my intake is oversized and my exhaust is stock i dont know how much performance difference it is because i had so much work done at the same time but most people told me its good for about 1/2hp gain.


with the curtis spark name you know it will cost alot..if your tight on money just get the 450r carb, i never heard of many people doing the yfz carb. the 450r carb has worked great for my g/f bike

[odog]

Originally posted by bens250ex
with the curtis spark name you know it will cost alot..if your tight on money just get the 450r carb, i never heard of many people doing the yfz carb. the 450r carb has worked great for my g/f bike yea it was very expensive $560 i believe but it was worth every penny to give u an example there is a strip about 3blocks from my house and in have a trail tech vapor comp/speedodemeter i was able to gain about 7mph in the same distance and with 16/38 gearing my bike use to only stand up easy in 1st and 2nd gear know i can get 1,2,3 and it will hop in 4th but not stand straight up like the other gears and the acceleration is real hard it pulls hard every gear.i mean it always pulled good since i made it to a 460 but know it pulls very hard like a modded yfz 450.but even if you dont get the fcr at least get the 450r carb. because a big kit that cant breath is useless i mean you will still have ok torque but half of 4th gear and 5th gear wont be that strong.i would also suggest a stage 3 cam unless your just looking for a lot of bottom end and some midrange. i rode 3 440exs that all had stock carbs and 2 of them had the stock cam (some of the funest bikes to ride) 1-3rd gear greastest bikes in the world but after that the fun is over reality sets back in.

[bens250ex]

On the set up in my sig I can get the front tires off the ground in all 5 gears . Now granted 5 takes some to get it up but it will do if fairly nice. It is a torque monster totally diff from my ltr it's nice to be in 3 gear on a sand hill and barely give it gas and it will pop up like nothin.gotta be careful I almost lost it once lol my g/f might get mad if I broke her bike lol

[Xplorer99]

wow alot of good info here pretty good you can do a wheelie in 5th gear! im setting mine up for more speed that torque... think its possible to outrun a 450r or 500 predator? lol maybe i should have went with the stage 3 hotcam, i only got the stage 2.

what exact timing chain to i need to get?

[odog]

Originally posted by bens250ex
On the set up in my sig I can get the front tires off the ground in all 5 gears . Now granted 5 takes some to get it up but it will do if fairly nice. It is a torque monster totally diff from my ltr it's nice to be in 3 gear on a sand hill and barely give it gas and it will pop up like nothin.gotta be careful I almost lost it once lol my g/f might get mad if I broke her bike lol what gearing are you using.and i guess if i sit at the back of the bike and give it a pull it will come up in fourth im a big guy i usally dont have to use 4th and 5th gear on the trails that i ride at.i was actually drag racing the first time my bike hopped in 4th gear. i know a few guys who are real good riders that can ride a wheele in all the gears but to have a bike come up when you dont want it too thats alot of power.oh yea i know there is alot of very fast 440s out there (im not comparing my bike to yours or saying yours isnt)i just had a very close friend that use to bye bikes race them lose and then sell them he actually had 6 different quads in a 7month period 3 440exs 1raptor 350 1 raptor 660 and 1 ltz 400. and by far his 440ex were the funest bikes to ride but not the fastest.my point to all this is any bigbore bike without the all the necessities to make it breath is pretty much useless.he could have kept any of those bikes and did a little bit more modding to them (except maybe the raptor 350)and he would have had a very fast bike.

[Xplorer99]

Originally posted by odog
what gearing are you using.and i guess if i sit at the back of the bike and give it a pull it will come up in fourth im a big guy i usally dont have to use 4th and 5th gear on the trails that i ride at.i was actually drag racing the first time my bike hopped in 4th gear. i know a few guys who are real good riders that can ride a wheele in all the gears but to have a bike come up when you dont want it too thats alot of power.oh yea i know there is alot of very fast 440s out there (im not comparing my bike to yours or saying yours isnt)i just had a very close friend that use to bye bikes race them lose and then sell them he actually had 6 different quads in a 7month period 3 440exs 1raptor 350 1 raptor 660 and 1 ltz 400. and by far his 440ex were the funest bikes to ride but not the fastest.my point to all this is any bigbore bike without the all the necessities to make it breath is pretty much useless.he could have kept any of those bikes and did a little bit more modding to them (except maybe the raptor 350)and he would have had a very fast bike.

actually had a good conversation with a friend about that... boring out doesnt do hardly anything performance wise, its all the modifacations that matter.

[odog]

Originally posted by Xplorer99
actually had a good conversation with a friend about that... boring out doesnt do hardly anything performance wise, its all the modifacations that matter. yeah the boring out is a minamal gain until u start the other mods my cousin has a kfx 400 that he doesnt know weather to get the carb first or the 432 athens kit.because he saw the difference on my bike but he also said both of them are a must have and he would be purchasing them soon

[bens250ex]

Originally posted by Xplorer99
actually had a good conversation with a friend about that... boring out doesnt do hardly anything performance wise, its all the modifacations that matter.

yup i can tell you first hand about it. i bored it to a 440 kept stock carb and cam and it wasn't much different, added the cam and carb and bam she woke up.

odog-i have stock gearing on it for now im about to jump up a couple teeth so first gear isn't so low. it has 20" tires out back as well.