Any Suggestions? 2003 YZ450F


11 replies to this topic
  • Mikeee P

Posted October 25, 2006 - 10:49 PM

#1

Looks like I'm getting a 2003 YZ450F. I read most of the threads I could pull up about the bike...

But anything in particular I should know/do when I get the bike?

I saw the threads on the clutch pull and cures with 426 items...

Anything else I should know about this bike?

Thanks guys.
Mike

  • scottbob99

Posted October 26, 2006 - 04:35 AM

#2

I have a JD jet kit and FMF full exhaust, it flat out rips!!!! I went 1-1 at Southwick last week in front of a lot of 06's. :mad:

  • elcamino76

Posted October 26, 2006 - 07:39 AM

#3

i have an 03 and its a great bike i havent had any problems with it yet, mines mostly stock. i have heard about the issue with the clutch, (slurging or something) i dont believe mine does that.

  • grayracer513

Posted October 26, 2006 - 08:10 AM

#4

The '03 had a couple of issues. One was the clutch that you already know about.

The other is a thrilling, but much too aggresive power delivery. This can be dealt with the easiest by substituting a Dr.D 8oz flywheel, or the GYT-R "offroad" flywheel (roughly 7.5 oz heavier than stock). Another, more expensive approach is a Vortex ignition, with which you can select from multiple timing maps to settle the engine down just a bit.

Otherwise, they are a good, reliable piece.

  • John407

Posted October 26, 2006 - 08:41 AM

#5

I have a bolt on 10oz flywheel weight and I changed the 48T rear sprocket for a 47T. I added 1/2 " to the clutch actuating arm and the old '03 is ready to go. (I also put on a step seat to hold my fat arse in place.) I've realized early on that if I do not get the holeshot, it ain't the bikes fault.

  • Ga426owner

Posted October 26, 2006 - 09:26 AM

#6

I have a bolt on 10oz flywheel weight and I changed the 48T rear sprocket for a 47T. I added 1/2 " to the clutch actuating arm and the old '03 is ready to go. (I also put on a step seat to hold my fat arse in place.) I've realized early on that if I do not get the holeshot, it ain't the bikes fault.


mine has the GYTR flywheel, 47 T rear sprocket, JD Jetting, power now, twinair power flow, Enzo subtanked suspension w/ Ti shock spring, RG3 clamps, Storm link, light speed pegs, Full Hinson clutch and now a 470 cylinder, and many more additions.....it is endless what you can do to make the 03-05 that much better.........:mad:

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  • elcamino76

Posted October 26, 2006 - 09:39 AM

#7

mine has the GYTR flywheel, 47 T rear sprocket, JD Jetting, power now, twinair power flow, Enzo subtanked suspension w/ Ti shock spring, RG3 clamps, Storm link, light speed pegs, Full Hinson clutch and now a 470 cylinder, and many more additions.....it is endless what you can do to make the 03-05 that much better.........:mad:


i didnt want to steal a thread or nothin but i was wondering if you needed to do anything else, like jetting ect.., when adding the power now??? thanks

  • Ga426owner

Posted October 26, 2006 - 09:45 AM

#8

i didnt want to steal a thread or nothin but i was wondering if you needed to do anything else, like jetting ect.., when adding the power now??? thanks


Keep in mind I am a VPU4 only user.....With the power now oh and quickshot( I forgot) and twin air powerflow I did have to tweek the Jetting...the JD Jetting kit solved all my woes...but it did take some time to test, re jet, test again, rejet again, retest.....once it was right I documented what mj/pj works best for what temp ranges and which JD needle to use and what clip position to use for temp ranges.....I will say the power now by itself was really not too noticeable...but with the quickshot, powerflow and JD kit it is very noticeable....much better throttle response, and more power...:mad:

  • Indiana

Posted October 26, 2006 - 11:22 AM

#9

I have only had mine for a couple of months but it is a great bike. Depending on what you're doing with it will determine what mods you'll want to make. I like doing the GP/HS stuff and have dropped the front sprocket to 13. That made a huge difference and for what I do made the gear ratios work much better. I also did the GYTR off road weight and shortened the bars a bit for the woods. I'm not an A level rider and the bike always bails me out when I probably should've been on the gas sooner! The only other things I think need a little work is the forks set up a little better and the brakes are a little mushy for my taste.

  • Mikeee P

Posted October 27, 2006 - 03:57 PM

#10

Great replies - thanks...

On a good (exciting?) note the 03 YZ450F I'm getting has the Eric Gorr big bore kit... what is that 272cc or something like that?

Ga426Owner, I think you said you had a 470 cylinder - is that the Eric Gorr cylinder or ?

What jetting are you running in Georgia and where are you located at? I'm in Florida (Cocoa Beach) but if you're in Atlanta or something like that, it'd give me a good starting point to look at jetting - the bike might already be jetted, I dunno... it supposedly has an exhaust on it as well - haven't seen it. Heard it was a Yoshi hope it's a full system - not sure if they make just a slip on.

Any other thoughts? I'm thinking the flywheel might be a great addition... I'll give it a ride and then prob go for a bolt on like a Steahley if it's as bad as everyone is saying.

I think I might be able to pick up a juice clutch (Magura) for a good price. If so, I might have to get one. I saw where some of you guys in other threads said the clutch pull was just unreal (super hard)... ???

Thanks for the tips so far - any suggestions on tranny oil? And is it as big a pain to fully change the oil as I'm hearing? Three different places have to be drained or checked or something like that?

Mike

  • Mikeee P

Posted October 27, 2006 - 03:59 PM

#11

Oh hey - one last thing.

What about the starting. Any issues with the "03" model or does it crank fairly easily? Should I be looking at a HotCam or anything to ease starting?

Mike

  • grayracer513

Posted October 27, 2006 - 04:31 PM

#12

note the 03 YZ450F I'm getting has the Eric Gorr big bore kit... what is that 272cc or something like that?

No, I think they're a little bigger than that. :mad:





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