THE RESULTS: My fully built Duncan 440ex vs a stock yfz450

[Big - D Racing]

I went out to the desert this past weekend with my friend and his new yfz450. The crap talking began a while ago about who would take who in a drag. My bike has been dynoed at 41hp and I have taken raptors, predators, some banshee's here and there, 250r's, and tons of z400's and 400ex's.
Here are my mods:

I have a 2001 400ex with a brand new Duncan racing 440 national kit installed that includes je 89.25mm piston at 12.5:1 compression, along with megacycle mx cam, full port & polish including 3 angle valve job, hardened rockers, titnium springs with short bronz valve guides, full hinson 8 plate clutch kit including removable side case, bsket, inner hub, and pressure plate, fst oil cooler kit, oversized vented oil tank, Doug Eichner Signature Series edelbrock carb, Curtis sparks x-6 exhaust with a k&n air filter. I believe that is it in terms of engine work. I run vp c-12 gas straight (108 octane) with 15-37 gearing.
My friends bike:
2004 Yfz 450 bone stock except for his airbox lid is removed.

The results:
Off the line I crush him, but by 3rd gear he is riding even with me and by 4th he is passing me. After multiple races it was the same results he would win by a couple of bike lengths. I was pi**ed off and impressed at the same time. We swited bikes and the result was still the same. The yfz fells like a 2 stroke, no where near any 4 stroke I have ever rode before. My bike has that killer torque and low end pull and his just doesn't really have it, but it has a top end I would compare to a banshee, but a lot smoother and useable. That bike rips. And with a few minor mods I can only imagine what can happen to it. When your on it, it also feels unlike any quad I ever rode. It feels more like a dirtbike because the body is so skinny and feels so light. I know it has less hp then my bike in terms of being on a dyno, but because the light weight size and feel it can just out run it :grr: I can't wait until the 450r comes out and I hope it crushes the yfz and if it does I just will have to get one, so I'm back on top:macho
Damn Yamaha's:mad: :devil:

[raptor_02]

well it's good to see that you are honest and will tell the truth of what happened. You need to tell your buddie to get a pipe and rejet his carb. Then race again and let us know what happens.

[remlapr]

I agree - good unbiased info.

I'd rather have the low end torque.....:o

[airheadedduner]

You might find different results hillshooting. My 440 in not as built as yours. THe shee's take me on the flats but put a hill infront of us and I can beat quite a few of them.

[Ralph]

on an mx track i dont go past 3rd-4th gear...

[twisted threads]

Originally posted by airheadedduner
You might find different results hillshooting. My 440 in not as built as yours. THe shee's take me on the flats but put a hill infront of us and I can beat quite a few of them.

Thats what I was thinking. The new Yami IS fast we all know that and on dirt or pavement it probley will woop up on my EX easy But you put a hill in front of you were the TORQUE plays a part and I bet you would win. But if the Yami has a pipe and the cam mod I dont think that barly NO 440ex's would be even close. Just my $.02:cool:

[AlaskaSpeed]

Nice, honest report. I know I drag raced my Old modded Cannondale and beat him since I installed the Sparks pipe. I pulled him from the line all the way though; and my Dale has beaten LRD built and dyno tuned 440EX's. The kid that owns the dale is about 80lbs lighter than me and has HMF exhaust and custom Moto/Speed mapping. The pipe and rejetting really made a difference in the low end...but the YFZ revs so damn fast that low end doesn't come into play for the most part if you ask me....and I have climbed many hills with it...letting off 3/4 of the way up and coasting the rest..........JIM

Originally posted by Rico
I'd rather have the low end torque.....:o

[AlaskaSpeed]

Originally posted by XxHonda_RacerxX

[hawiianpwr]

I just rode a yzf 450 this weekend with a pipe jetted and open airbox. All I gotta say is hes right! It revs super fast and just keeps reving the power never drops off. Its really going to be interesting when the 450r comes out

[skemp]

My guess is the Yami might end up having more power because that is just Yamaha's tradition. Make more power while sacrificing in other areas such as handling, longevity, price, etc. I am sure the Honda will be an avid competitor either way.

[cals400ex]

Originally posted by skemp
My guess is the Yami might end up having more power because that is just Yamaha's tradition. Make more power while sacrificing in other areas such as handling, longevity, price, etc. I am sure the Honda will be an avid competitor either way.

i agree, i would put money on the yfx being faster.

[GlamisEXRider]

Hill or no hill the bike is fast. i was out at glamis last weekend and raced 3 or 4 450's and lost every time except once were he probably mis shift or something. I know one was piped and 2 were stock.
We would take off even but by the time we got to the top of the hill he had 3 to 4 bike lengths on me and that was most of the time. I hate to say it but i even got beat by a girl on one. power to weight ratio kicked my butt.
they are fast don't race one if you don't have too if you do be prerared to lose.

[norcalatver]

I haven't lost to one yet! But of course I have an FDO built 493 stroker! It kills most all 4 strokes. Only alcohol DS's and banshees were beating me @ Sand Mountain.

[JOEX]

Yes, very nice to see a post like this:)

I'm wondering what the results would be if you ran the stock gearing, 15/38 or with other gearing such as 16/38 or even 16/37. You may have the torque to pull that.

Joe

[Big - D Racing]

i was also thinking of that and I do have a 16 renthal front sittng in storage that I just might have to put on and try another drag.

Ny yfz is definatly faster than my 463ex. But as of right now I am still faster on my ex in the woods. I really think that with a little bit of time and work I will be faster on the Yfz. The yami is def faster and lighter. but It has a 2 stroke HIT that will wear you out much faster. My Ex is extremely smooth and easy to ride with Great power. With all of that said i show up at the track every weekend on the YFZ and will continue to do that.

[400grl]

I rode a YFZ last weekend, and I was totally surprised at how fast that thing revs!!!! It felt similar (not quite, but close) to the custom built 450 I had also ridden. Revs quick- sits low - felt really good for a Yamaha. I would bet the Yami will be faster than the Honda, too....but....I've always picked Honda for all the other reasons (handling, quality, reliability). Everyone else here is buying YFZ's....so....I may have one of the only 450R's on the track....COOL! :)

[AlaskaSpeed]

Originally posted by 400grl
I rode a YFZ last weekend, and I was totally surprised at how fast that thing revs!!!! It felt similar (not quite, but close) to the custom built 450 I had also ridden. Revs quick- sits low - felt really good for a Yamaha. I would bet the Yami will be faster than the Honda, too....but....I've always picked Honda for all the other reasons (handling, quality, reliability). Everyone else here is buying YFZ's....so....I may have one of the only 450R's on the track....COOL! :)

Ya just have to be different....lol....

I look forward to next season and seeing some of the new Hondas too. Suppose I could buy one and keep it hidden from the wife if I really tried....:devil:

[Out_Sider]

are you rich or somin???? because you have a brand new yfz with ALL THOSE MODS!!:eek: that mofo must go!! and your talking about how you could get a 450r also...u rich ***:blah: lol

[AtvMxRider]

Originally posted by Out_Sider
are you rich or somin???? because you have a brand new yfz with ALL THOSE MODS!!:eek: that mofo must go!! and your talking about how you could get a 450r also...u rich ***:blah: lol


It's called a job maybe you should try one........:huh

[Doibugu2]

Originally posted by AtvMxRider
It's called a job maybe you should try one........:huh

What's that about. I have a job, and I don't have a two cannondales one year, then a new YFZ.

If you have job why are u still riding an old '00 honda?

[AtvMxRider]

Originally posted by Doibugu2
What's that about. I have a job, and I don't have a two cannondales one year, then a new YFZ.

If you have job why are u still riding an old '00 honda?


Well maybe you need to take reading lesson cause I don't have an "old 00 Honda":rolleyes:

[Doibugu2]

Originally posted by AtvMxRider
Well maybe you need to take reading lesson cause I don't have an "old 00 Honda":rolleyes:

Must have been a smudge on my brothers computer screen. I see it's a '02 now.

My bad!:D

[AtvMxRider]

Originally posted by Doibugu2
Must have been a smudge on my brothers computer screen. I see it's a '02 now.

My bad!:D

LOL ;)

[Steven]

Here is another unbiased report, for I own both bikes.

The YFZ450 is very much faster than my 440EX in all categories.

Funny thing is that I used to "feel" that my Honda was fast. Now it feels slow to me but it isn't. I keep thinking something is wrong with it, but there isn't. It still runs with DS650's, Raptors, Predators ect... The difference is that the Yamaha runs from these bikes, no problem. My Honda is just old school and decade old technology. The Yamaha and new Honda are state of the art.

The amazing/disheartening thing about the YFZ is that by retarding the exhaust cam one tooth, adding a slip-on pipe, removing the air-box lid, and rejetting ($250), you've just added between 10-12 wheel hp through the powerband. It really BLOWS by my beloved fourtrax. The engine designe is really showing its age.

Its not all about power either. These newer liquid cooled, nickasil, skirtless piston engines rev out so fast. They feel like 250R's with broad torque.

If I didn't have so much money in the TRX440EX, I would get rid of it. Problem is its not worth anything anymore so I'll keep it untill it dies.

[CoorsMan]

so the yfz 450 bet a 440ex in a straight line. The question is can that yfz 450 hang with a 440ex with a expert rider, on a tight course? well?

Who needs to be the fastest? I don't nedd to go fast, I just like to ride and have fun, with the poeple that enjoy the same.

Coorsman

[andrew360]

Originally posted by CoorsMan
so the yfz 450 bet a 440ex in a straight line. The question is can that yfz 450 hang with a 440ex with a expert rider, on a tight course? well?

Who needs to be the fastest? I don't nedd to go fast, I just like to ride and have fun, with the poeple that enjoy the same.

Coorsman

I am on the same page as mr. CoorsMan about just having some fun; sure, being the fastest/best is a lot of fun, but I'm just out there to poke around and have a good time:D



just my .02

[RMX500]

holy revive a dead topic..

[tbainer]

I have beat four or five 450's in the sand. We race a boxcar hill which is about 100yards up hill and haven't been beat by one yet. They are really fast though. They are the only fourstroke that can give me a run for my money.

[cals400ex]

Originally posted by tbainer
I have beat four or five 450's in the sand. We race a boxcar hill which is about 100yards up hill and haven't been beat by one yet. They are really fast though. They are the only fourstroke that can give me a run for my money.


what jetting you running and who did the port work?

[tbainer]

I had a friend of mine do it who has been building race car motors for over 30 years. I also just added a 39mm fcr. My main jet is a 185

[twisted threads]

Originally posted by tbainer
I have beat four or five 450's in the sand. We race a boxcar hill which is about 100yards up hill and haven't been beat by one yet. They are really fast though. They are the only fourstroke that can give me a run for my money.

At box car my 440ex was beating stock YFZ's fairly easy and the ones with pipes and who knows what other things thay have done the race is close. My 440ex has a harder time on the flats Vs the yfz they are a fast bike HANDS DOWN. On the flats it has alot to do with the start, with a stock swingarm It really hard to keep the front wheels on the ground. Last weekend one of my little brothers was down at CoosBay and he said there were two really fast YFZ's down there that were king 4stroke at the hill so Im sure my EX has met its match but then I get the R out.:cool: