More power! KFX dogs me

[Raptor4439]

Went ridin yesterday with a few friends, heres the bikes: red 440ex (mine). KFX 400, and a 92' timberwolf. My 440 has a bore kit, turf tamer rears, nerfs, bumper, shaved front fenders. The KFX has holeshots all the way around and other than that it's stock. Me and the kfx raced twice, the first go around I started off in 2nd on a flat field, I jumped him off of the start and he caught up by 2nd gear, then we stayed side by side until about 4th or 5th, after that he left me in the dust. On the second race I started off in 1st gear and I did worse than before. I have a job now so I can get some more parts for my 440 so I can beat the KFX. What are the "BEST" parts for the price for a 440, remember I have the stock cam, stock carb, stock pipe, so the parts im going to buy are going to be spaced out pretty far so I need parts that comtemplate (sp?) each other until I can get all of the parts. Can somebody help me out?

[mustang]

who built your 440? you should be wrecking that thing

[zephead400ex]

Originally posted by mustang
who built your 440? you should be wrecking that thing

He is still running the stock exhaust along with other stock powertrain components. I would be sure that if he would at least get an aftermarket exhaust the 440 will wake up and fly by the stock KFX.

[adrenaline]

def go out and buy a pipe with the 440 the stock pipe prolly isnt cooling or letting gasses out fast enough you got to remember the stock pipe is meant for the 397cc stock engine...second get it jetted, and a aftermarket air filter K&N with outer filter or a uni filter..you should be killing your friend during the entire race..maybe get your valves adjusted they might be off..cause i ate my friends KFX on my 400ex and all i have is jet K&N and slip on..hope i helped a lil :devil:

[honda_74]

Get a full exhaust. And a cam also..while you have it apart, put a bigger timing chain in it. Ported and Polished. All but the exhaust shouldnt be over $250. The exhaust will vary depending on what you buy. Mine came alive once I did this to my old one.

[Atreyu]

I would stick with the engine builders pipes (IE:Sparks, LRD, Duncan). Also, HMF's aren't bad. Stay away from DG and Cobra. I would go with a stage II cam too. A ported head wouldn't be a bad idea either.

learn how to ride ;)

[adrenaline]

Originally posted by Jumbo747
learn how to ride ;)

haha that was awesome

[hondarider2006]

get a pipe and cam. With my setup I stay even with a KFX....so with this you should be able to smoke him;)

[michigan rider]

has anyone sugested a pipe??? lol cause thats what you need

[hondarider2006]

the e-series has some good power gains, but its not a "top" quality pipe IMO. Look into HMF if you want a descent pipe, that will last and have power. Or if you have the $, a sparks would wake your bike up big time. A lot of people would recomend the Wb e-series, and I will admit it has been a good pipe, other than it falling apart. I do have the "newer" pipe with the added supporting brackets, and they didn't do chit. All 3 of they cracked. My buddies pipe did the same thing. I think a lot of people on here have experienced problems with there e-series falling apart, and would recomend a sparks or HMF over wb....:o

[Raptor4439]

I'll look into the HMF exhaust. This was my first engine rebuild where I had to set the valve clearences and jetting and im new at engines period so I think I screwed up somewhere. When you open the caps on the top of the engine that screw off to the valves how are you supposed to set them? I know I set them before with a feeler gauge with .004 for the intake and .005 for the exhaust. Since I have to bend the gauge to get it in there I can't seem to get em right. How much play is the feeler supposed to have when I get them "tight"?

[cals400ex]

i always make sure i can't squeeze the next size in. for example, on the intake i make sure i can't get .005 in.

[Raptor4439]

Originally posted by cals400ex
i always make sure i can't squeeze the next size in. for example, on the intake i make sure i can't get .005 in.

oh okay. dunno why I didn't think about that before but anyway :rolleyes: does a 134DJ main sound right cal? this has been bothering me for a while, that stock is a 148 and im having to run a 134dj main to get the spark plugs to stop fouling out. could it be the stock pipe? :confused:

[pnut420]

I had the HMF on my brothers stock bore with 39mm and also had the sparks, the sparks seemed to make a little more power. On the 440 bore the HMF should be a good pipe though because it has a larger diameter headpipe than the X-6 and it a little quieter. I would also do a mild port job and do a stage 2 cam as well as a CRF timing chain. Other than that maybe a FCR or have your stock carb bored out

[Raptor4439]

If I buy a bigger pipe for the 440 it should stop the jetting problem I guess. I'm leaning towards the HMF because it has good power for the price. Okay about the carb.. is it a must to bore it out or have a new one? and if I bore it out is that a cheaper alternative to a new one or should I just buy a new one?

[montyjcm]

Check out this thread it has a lot about carbs!

[montyjcm]

probably would help if I posted a link:D http://www.exriders.com/vbb/showthread.php?threadid=93898

[ReconRider25]

i think you need a cam.;)

[Smokin 440]

What you need...
1) Pipe, i reccomend wb e series promeg, hasnt broken, sounds great, you can take off the spark arrester, i have nothing bad to say about it, or get a sparks(rejet)
2) K&N airfilter - the airbox lid + outerwares (rejet)
3) Cam, for like $100 a stage 1 or 2 hotcam depending where u ride (rejet)
4) possibly a p&p and chain but not necessary (rejet)

With those things u will smoke a kfx if u gear up a little, with my old 440 with all that stuff with a stage 1 cam, but no p&p i could sit next to a topped out z 400 while i was in 4th gear, and i shifted to fifth and well u get the point...

[Dunesurfer]

Exhaust: Sparks, Duncan,LRD, White bro pro meg
K&N filter with outerwares-remove airbox lid
Hotcams stage 2 cam
Porting
Rejet 170-180 at sea level
FCR 39 carb
Higher compression piston
.
With just an exhaust and filter. After rejetting you shoud kill a stock kfx

[Raptor4439]

Originally posted by Dunesurfer

Higher compression piston

I already have a 11:1 Wiseco piston in there bored out to a 440. as is with the stock pipe and the only power mod is the 440 I can stay side by side until he kicks it into fifth gear. If I get a pipe how many ponies will that let go? just curious...