My latest Classic Steel covering Yamaha's 2003 YZ450F is live!

Love these, keep up the good work!

That was one of the least favorite bikes I’ve owned. 

I picked up an ex race team bike, virtually stock when I got it.

After Racetech did their work on the suspension to suit my slow fat arse it was a brilliant bike.

It ran forever.......

I loved this bike and it was a beast. I have a 2004 YZ450F that I am doing a full rebuild on and looking forward to riding it this summer, I hope....Looked for one for a long time-they are tough to find in decent shape but this one was in really good shape so a good candidate. Would love to find some SSS suspension and bolt it on, from a 2006-09 450 or 250F.

I hated mine. 
 

I eagerly traded my YZ426f for one of these…what a dissapointment..,

thanks blaze!

Agreed what a pile of shit . I broke 2 Kickstarter s and it handled like shit . It was fast though 

Thanks, brings back good memories and bad.  20 years already - super fast and difficult to keep in a rut.  I was alone in loving the 4 speed for motocross - holeshot machine

Nice work.

...man, that muffler is Yuuuuuuge....     Mkes the bike look rear-heavy.

Magoofan:  I thought the exact same thing. Those older 4 strokes look so weird with a Howitzer protruding out of the rear end. Lol. It looks comical compared to the current bikes. Haha

Have you seen the current gen KX's?

 That's the first thing that came to mind followed by those awful 2 stroke FMF silencers.  

I kept clipping it with my boot, so I cut 3 inches off.  Looked much better and didn't get in the way anymore.  Was not louder nor did it change performance!

We had an 04 that we bought new. I sunk that thing in a wash in moab completely up over the handlebars. We ended up getting it running and rode it out. Had to change the oil 10 times but it still ran before my old man gave it away to his buddy.

I had that bike, main thing I remember was the flywheel was way too light and it would stall so easily. I got a GYTR flywheel weight and it made a huge difference. 

Bike was crazy fast tho, this was back when most people had 250 2 strokes, i'd just roll her nice and easy out the gate then pin it wfo. Holeshot everytime 

Hi, the description of that machine it's perfect, I have one at around 8years now, I stopped racing at 17years and from that time I had 2 KTM and after picked up this YZ 450F,  I don't have felt necessary buy a fuel Injection with batteries and a lot more parts prone to failure, carburetor bikes are much more reliable.

Of course in mine I made already chassi and 2 engine rebuilts

On mine I have made some minor modifications through these years, and now I feel that I'm riding a 250 2 stroke but with a lot more torque and a lot wider power range! With that engine I get pleasure, but I can't loose the respect on him ( very different from my KTM 450exc 03, it runs good, fuel economy, but engine was slow and not provided any emotions)

Comparing that Yamaha YZ 450 2003 to these new 450 motorbikes I only felt 2 negative sides.

1- suspension

2- maneuverability in air ( on the ground I feel it very light, nothing like the reviews that says that this bike won't turn) on the air it feels heavy and difficult to put back on line, I think it was designed to go straight always, like a dragster car 😂.  Mass centralization make a big role here, again, new bikes are more evoluted in this area.

Not my favorite Yamaha 450. I actually like the 426 better in hindsight . I do recall passing other 450's pretty easily in open sections on practice days. Very fast bike

I worked for Yamaha at the time and got to attend the media launch of this bike at the WB Ranch (Lake Whitney Motocross Park).  Got to do a ton of riding and made some great memories that week.

The modifications I have made to this bike are very simple:

1-Clutch lever on engine extended ( more leverage equals to less force + more control on clutch engagement, at the cost of reduced clutch course, through running, need adjust the clutch several times through different temperatures, but it's a lot more light.

2-protaper handlebar with low profile, turns better and helps keep the front wheel on the ground, with adjustable levers.

3- shortened exhausts 5cm, never liked the extra long exhaust, + the mass is more on center now+ reduced back pressure raised the torque peak, in practice and in addition with a 178 main jet, I felt more power in all the rev range.

4-steel brake line on the front from a KTM, and different route, here I felt the brake more direct.

5- putoline 2.5w on the shock, and 5w on the fork ( and many hours to get it worked really well for me)

6- front lowered to the first line

7- air screw that I can adjust Avery time, I run a bit more rich always, so it starts easier, more difficult to stall and the engine runs cooler

And after this small adjustments I simply love the bike, I'm not planning to change it, probably next step is new kayaba SSS forks, and I have my dream bike.

I never tried the YZ 426, but I ride many times a friend wr 426( with YZ spec jet and needles) but for me I can't compare both, because between the ride of his bike and my 450 are 20 years difference in my age. But I remember it was very fast to.

Here's a video from a Sunday, before I open the engine to change gearbox ( 3 and 4 were not good)

Valves, rings , chain guides... I have a brand new motor this Year, and with 15/43 transmission, now it's really fun the engine.

Yes, it's a good Enduro bike too...