Drag race 03/04 vs 05 YZ450?

[Joe_Jet]

Has anyone done a good comparison between the 05 and either an 03 or 04? How much did they mellow it out? I hope the 06 is more like my 04.

[Sparky_So_Cal]

For what's it worth, I have race my bike on 4 occasions (05 yzf450). Each time w/ over 25 guys on the gate. Out of a total of 8 starts I have obtained the following.

3 holeshots

2 seconds

2 fouths

1 horrible gate pick, mud bog.

These starts were at Hollister and Glen Helen. Glen Helen is a very long straight. The only performance mods I have done is the JD jetting kit. My bike hauls the mail.....and deliver's on Sunday also ?

The bike is extremly quick and fast.

[mikedabike]

I have an o4 and my buddy just got an 05. I rode them both all day yesterday, many drags switching bike, different traction conditions etc. Any difference would be splitting hairs. The 05 does seem to come on the power a little lower and a little smoother it is still just as fast as my 04 without as much of a hit in the middle.

[Joe_Jet]

That sounds promising. Maybe the smoothness is deceiving? If the 06' gets the AL frame it should be really sweet!

I love that start at Glen Helen!

Man, I can't wait to get back to riding! Doc still says March.

Thanks,

[hvyw8t]

I have an 04 and recently rode an 05. The power difference isnt much. If anything the 05 seems to feel alittle bit crisper and smoother, but is still just as fast as the 04.

[Guest Dolphin]

HI,

Did you notice a big difference in your 05 YZ450F when you installed the JD jetting kit and if so can you describe the difference. I recently purchased an 05 YZ450 and have been pretty pleased with it. Have you notice the rear end kicking on small sharp bumps and hack??

Thanks,

Marc

[Idaho_Wolverine]

My 03' is the only yz450 I have rode. All the things I have read though, about the "light flywheel" and "too much snap" on the 2003 YZ450F makes me curious if my 03 is quicker than the "smoothed out" 04 and 05 bikes.

[grayracer513]

My 03' is the only yz450 I have rode. All the things I have read though, about the "light flywheel" and "too much snap" on the 2003 YZ450F makes me curious if my 03 is quicker than the "smoothed out" 04 and 05 bikes.

The '03 and '04 are identical engines except that the '04 has the GYT-R 5oz heavier flywheel already on it as delivered. The '05 has had the exhaust cam timing tweaked and the ignition remapped.

The problem with the '03, and to a lesser extent, the '04, is that they come on so hard right at the bottom that they have a tendency to rip the rear wheel out of the ground, somewhat like a big 2-stroke. They are, in fact much more controllable than that, once you learn them. The mods to the '05 are intended to move the same power a little farther up the curve, makng it slightly less aggressive at low speed, and hopefully, a little easier to control. Each of the 3 has about the same peak power.

[Texas4play]

HI,

Did you notice a big difference in your 05 YZ450F when you installed the JD jetting kit and if so can you describe the difference. I recently purchased an 05 YZ450 and have been pretty pleased with it. Have you notice the rear end kicking on small sharp bumps and hack??

Thanks,

Marc

Check your rear shock rebound. If it's too slow it'll kick.

[226DAD]

Never been on a 03/04 YZ450F, only the 05. Seems to be very soft on the bottom compared to KTM 450SX. Riding the YZ and SX back to back, the SX kicks the YZ's ass on starts and straight line drag races, KTM defintely has the most power. That said, my son (a top 3 250B rider) prefers the YZ overall, but wishes he could have the KTM powerplant in a Yamaha chasis.

[gonzo]

I have an 03 that I smoothed out with the help of an FMF pipe and 6oz flywheel. I hear the 05 feels just like my bike. I never felt at a loss of power.

[Satch0922]

I have ridden the 05 and the power is electric and deceptively fast. When I got back on my 426 (which isn't stock as you all know) the 426 "felt" faster. Of course actual "speed" on the track has alot to do with how the bike is set up (bars, suspension, tires etc).

One thing is for sure....the new forks are sweet!!!!