Power differences 2003-2007 ???

I'm a Honda guy, however, I have always dug the Yammies too. I'm thinking of getting a 2003 or 2004 450 because they were supposed to be so gnarly. I have seen some old dyno charts in the mags and yes, I know that dynos do vary from one to another. It looks like the bike was pumping out about 47 to 49 HP which is less than my 2007 CRF 450 AND THE 2006-2007 yz 450. I have never rode on of those beast, so I can only assume that it just had a crazy shot of torque from the bottom to the top? So who here has rode the Hondas the Yammies and even that 2007 Kawi 450 that was supposed to be a monster? If you could give a seat of the pants description, that would be great. I was running a Service Honda CR 500 2 somkie back in 2004 and it was just one big heap of torque for about 2 seconds and then you shifted. My CRF 450 would beat in a drag race everytime once it was in 3 rd gear and singing in that killer mid range. I would bet that the 2003 YZF 450 would destroy it?

Thanks for the input.

First off, the only possible way a reasonably stock CRF, YZ, KX, or xyz450 will beat a good running CR500 is by out biting it. Traction was the same problem for the big CR in 4th gear that it is for most 450's in 2nd. Having run mine on the streets in the Elsinore GP, I can tell you that there was no motorcycle at that event that I was unable to pull at least 8 bike lengths on going down Main Street.

But be that as it may. Everyone who has ridden my '03 offers the impression that it is significantly more powerful than an '06 YZ450. The throttle is like a trigger, almost switch-like, like a 1970 454 Chevelle. A lot of fun, but very difficult to manage, and not as truly effective as the "milder" '06, which interestingly has 2-3 more hp on a dyno than the '03 does.

In a side by side rolling second gear start on pavement my '03 and either of my '06's run dead even until mid 3rd, then the '06 starts pulling away. But no one would ever guess that by riding them back to back.

First off, the only possible way a reasonably stock CRF, YZ, KX, or xyz450 will beat a good running CR500 is by out biting it. Traction was the same problem for the big CR in 4th gear that it is for most 450's in 2nd. Having run mine on the streets in the Elsinore GP, I can tell you that there was no motorcycle at that event that I was unable to pull at least 8 bike lengths on going down Main Street.

But be that as it may. Everyone who has ridden my '03 offers the impression that it is significantly more powerful than an '06 YZ450. The throttle is like a trigger, almost switch-like, like a 1970 454 Chevelle. A lot of fun, but very difficult to manage, and not as truly effective as the "milder" '06, which interestingly has 2-3 more hp on a dyno than the '03 does.

In a side by side rolling second gear start on pavement my '03 and either of my '06's run dead even until mid 3rd, then the '06 starts pulling away. But no one would ever guess that by riding them back to back.

might be wrong, but your 03 has a 500 hundred kit on it right?

might be wrong, but your 03 has a 500 hundred kit on it right?
Wrong. GA426owner has an '03 with a 470 kit. Mine's stock other than the exhaust and heavy flywheel.
Wrong. GA426owner has an '03 with a 470 kit. Mine's stock other than the exhaust and heavy flywheel.

Weren't the 04 yz450's the monsters? I have never ridden one.......only heard the stories. On the other hand, my 1983 Maico 490 was the the fastest dirtbike i've ridden. My old 1984 CR 500 was a close second. That thing would eat a rear tire in one ride.

I'm a Honda guy, however, I have always dug the Yammies too. I'm thinking of getting a 2003 or 2004 450 because they were supposed to be so gnarly. I have seen some old dyno charts in the mags and yes, I know that dynos do vary from one to another. It looks like the bike was pumping out about 47 to 49 HP which is less than my 2007 CRF 450 AND THE 2006-2007 yz 450. I have never rode on of those beast, so I can only assume that it just had a crazy shot of torque from the bottom to the top? So who here has rode the Hondas the Yammies and even that 2007 Kawi 450 that was supposed to be a monster? If you could give a seat of the pants description, that would be great. I was running a Service Honda CR 500 2 somkie back in 2004 and it was just one big heap of torque for about 2 seconds and then you shifted. My CRF 450 would beat in a drag race everytime once it was in 3 rd gear and singing in that killer mid range. I would bet that the 2003 YZF 450 would destroy it?

Thanks for the input.

I rode a 07 CRF450 sunday which had 52.7 hours on it, and I personally thought my stock 100+ hour 06 YZ pulled harder all the way through.

Like grey said though, the 03 feels faster then it is due to the way it delivers its power.

Weren't the 04 yz450's the monsters? I have never ridden one.......only heard the stories. On the other hand, my 1983 Maico 490 was the the fastest dirtbike i've ridden. My old 1984 CR 500 was a close second. That thing would eat a rear tire in one ride.
The '03 was the bad boy, but in reality, there's not much difference between an '03 and '04.

i just got a stock 04 yz450f and thanks to grays help its running sweet.. i had a 125 previously and most people were saying the 450 has alot of balls.. maybe its me but they are not that monstor, bar throwing animal like people say they are. they are fast and powerful but i think having a 5 speed woulds help it alot.. the people i ride with have 04 yz450f, 06 rmz450 and yz426f and the 426 pulls harder then the 450s because he has the extra gear.. i love this bike compares to my 125 but the 125 had better acceleration

i just got a stock 04 yz450f and thanks to grays help its running sweet.. i had a 125 previously and most people were saying the 450 has alot of balls.. maybe its me but they are not that monstor, bar throwing animal like people say they are. they are fast and powerful but i think having a 5 speed woulds help it alot.. the people i ride with have 04 yz450f, 06 rmz450 and yz426f and the 426 pulls harder then the 450s because he has the extra gear.. i love this bike compares to my 125 but the 125 had better acceleration

The extra gear has no effect on how "hard it pulls".....5 speed or 4 speed, power is power. The top speed difference between the two ('03/'05 and '06+) is negligible (only a couple mph). If the ratios are slightly closer, you will find yourself running a smaller rpm range (but shifting more) on the 5 speed.

I've got a 03 and 04 they both have tons of torque alot more than the later models i've rode. the 07 kx has alot of pull on bottom but thats about it the 08 kx is very mild compared to the 03 and 04 the only advantage to them are weight they feel about 20 lbs lighter.And I would pick the 04 any day over the 03 because of suspention 48mm on the 04 and 46mm on the 03.Its like day and night.put on a carbon pro exaust and freakin hang on

I had an 03 YZ450 and now have an 06 YZ450 and the 03 felt much faster--absolutely no question about it. My 06 is easier for me to ride and thus more consistent lap times.

The '03 was the bad boy, but in reality, there's not much difference between an '03 and '04.

true I believe Yami added the 5oz flywheel weight to the 04 to tame it slightly....and remapped the ignition for a slightly less hit....and slightly better suspension

bottomline...03/04 will be faster but wear you out twice as fast trying to keep same pace....06/07 will be smoother and although fast you can keep the race pace longer....:thumbsup:

I ride a '03 YZ450 and have no complaints at all. The '03 is the last year that there compresion was 13:1 . All the new ones are about 12.3:1.

I had an 03 YZ450 and now have an 06 YZ450 and the 03 felt much faster--absolutely no question about it. My 06 is easier for me to ride and thus more consistent lap times.
Like I said, there's no question, everyone agrees, the '03 feels faster. In fact, it's not, and it's worse in the dirt than on the asphalt. The new bikes pull harder without the drama.
true I believe Yami added the 5oz flywheel weight to the 04 to tame it slightly....and remapped the ignition for a slightly less hit....and slightly better suspension

bottomline...03/04 will be faster but wear you out twice as fast trying to keep same pace....06/07 will be smoother and although fast you can keep the race pace longer....:thumbsup:

All '03-'05 models used the the same 5TA-85550-00-00 flywheel. In spite of the fact that Yamaha advertised an increase in rotating mass to smooth out the performance, the only part of the rotating engine assembly that was any heavier was the rod bearing and the big end of the rod. All the rest of the parts are the same. Fooled me for quite a while, too.

They did do a remap, though, and the 48mm fork is more than slightly better. Nothing like the new ones, though.

I totally agree with your "bottomline" statement.

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