It's Here...the 2010 YZ450F

I wonder what sort of metal they have that's translucent. :busted:

Must be a stone age metal polymer from the Mongolian NASA program.

I think the bulb at the beginning of the header helps to drop the sound a couple decibels, like the cylinder style on some bikes... Maybe...

are 450 that thirsty?
A 450 will get roughly 20-26 mpg off road. When my son had a YZ250F, the joke was that it didn't use gas. :busted:

14-volt 110-watt stator!! I'm hoping that new stator can be retrofitted on the 06-09 yz450's.

No matter what, you have to give yamaha some serious props for all these radical changes from the current MX bike norm...

Blue not Red though huh :busted:

Blue not Red though huh :busted:

First time I've liked the blue over the white...

Actually, it's about exactly that. Offsetting the cylinder as has been done here clearly reduces piston skirt thrust. It also allows the use of a shorter rod while maintaining the less acute rod angle of a longer one, which is about piston speed, as you say. Longer rods are generally a better choice for high RPM power, as is a more over-square engine (bore larger than stroke), which was also done here. Offsetting the bore is another way to arrive at the same result.

Discussion of rod length/angle (section 3 of the post):

You're right, but I'd think it allows longer cam overlap and buch of other benefits. Don't know how they exactly affect the overall process, but it's clear that they're done together with tuned intake and exhaust. At least after market pipe manufacturers have to work for their money now :busted:

ps. HID lights need battery to light up. No alternator can alone provide enough current.

Good looking bike and major changes..I'll bet it's a winner for sure. Just wish it had a few more pounds taken off. Still, hats off to yamaha.

Usually FI means metal gas tank. Thats a couple pounds right there. And I do wonder about the hotseat...?

Aluminum is metal, and it's lighter than plastic.

^^im pretty sure that even with 7 pounds gained, the weight has been shifted around, lower in the chassis, for better handling and an overall "lighter feeling" and more responsive machine.

It's still 5 lbs lighter than the kx and a couple less than the rmz.

Good looking bike and major changes..I'll bet it's a winner for sure. Just wish it had a few more pounds taken off. Still, hats off to yamaha.

I like the blue better two this year. yeah i bet the bike feels lighter too, even though it weights more. Thats most of the reason why two strokes feel so light.

ps. HID lights need battery to light up. No alternator can alone provide enough current.

..Or a big DC capacitor

The stator looks to be fully wrapped. 110W is good for two 35w HID :busted:

However, looking at the reg on the bike, I bet the bike is setup to run on AC only. If that is the case, there goes the HID as they need DC power only.

I wonder if the bike can be wired for both? or just DC?


You might want to leave a few of those watts available to run the E.F.I.

MSRP* $8,090 (White/Red) Available from September 2009

$7,990 (Team Yamaha Blue/White) Available from September 2009


Type 449cc liquid-cooled DOHC 4-stroke; 4 titanium valves

Bore x Stroke 97.0 x 60.8mm

Compression Ratio 12.5:1

Fuel Delivery Yamaha Fuel Injection (YFI), Keihin® 44mm

Ignition CDI

Transmission Constant-mesh 5-speed; multiplate wet clutch

Final Drive Chain Drive


Suspension/Front KYB® Speed-Sensitive System, inverted fork: fully adjustable, 12.2-in travel

Suspension/Rear KYB® Fully adjustable single shock; 12.4-in travel

Brakes/Front Hydraulic single disc brake, 250mm

Brakes/Rear Hydraulic single disc brake, 245mm

Tires/Front 80/100-21-Dunlop® D-742FA

Tires/Rear 120/80-19-Dunlop® D-756


Length 86.3 in

Width 32.4 in

Height 51.6 in

Seat Height 39.3 in

Wheelbase 58.7 in

Ground Clearance 15.0 in

Fuel Capacity 1.6 gal Just like Honda

Wet Weight 245 lb???

This is kind of cool:

^^im pretty sure that even with 7 pounds gained, the weight has been shifted around, lower in the chassis, for better handling and an overall "lighter feeling" and more responsive machine.

I wonder what the capacity of the new fuel tank is?

I doubt its going to be that much bigger, being a race bike.

But the aftermarket tank guys better get out their shoe horns!!

Hats off to Yamaha...They started a buzz, threw in some humor, and delivered one bad a$$ bike when they said they would...

I would totally buy one if I wasn't so freaking happy with the one I've got!

Definitely in a few years...

Fuel Capacity 1.6 gal Just like Honda and Suzuki

Wet Weight 245 lb??? = Curb weight or ready to ride weight.

dry is 234. 245 is wet weght

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By Zack Ailing
      hey guys just picked up a new project bike. Its a 2008 Yz450f with a big bore kit and a stroker crank. The total cc of the engine is now 499. It runs on race gas and will be an absolute monster when shes ready to rip. I will continue to make more videos on the bike so stay tuned Link to the video: 
    • By High On Octane
      2005 YZ450F, Athena Big Bore, Power Bomb, Q4.
      Ok.  Last fall after a decently hot day at the track, I noticed coolant leaking from the weep hole on my water pump after pulling into the pits.  Ordered an Athena re-seal kit, put it all back together and didn't really get a chance to ride it.  3 weeks ago, went out to the track, and after about 20 laps, it started leaking again.  Kept filling it with water to get thru the day, never ran anywhere close to dry or empty, jut a cup or 2 low.  Ordered a Hot Rods re-seal kit with bearing and also ordered a new w/p shaft.  Did it all again and got it back together, ran it, and as soon as it got to temp, it was leaking out of the weep hole again.
      So, what the heck am I missing?  I'm totally stumped on this one.  Is something wrong with my case cover?  Do I need to replace the w/p itself?  I'm feeling like I should've just ponied up for the Boysen in the first place, and now it's biting me in the butt.  Any help or suggestions is greatly appreciated.  Thanks!
    • By Awheeler25u
      Alright guys, my 04 YZ450f runs fine minus some slight backfires when decelerating (need to adjust fuel screw). The other day when I was done checking my valve clearances I changed the oil and filter and put the bike back on the stand, kicked it a few times without the ignition coil in to get some oil flowing got off and noticed a little drip spot on the ground, it was no bigger than a dime so I thought nothing of it. Started the bike with no issues took it for a quick 10-15 min ride, came back to the garage to find out my whole case was soaked with oil and it started pooling in the low spots on the clutch basket side. I cleaned all the oil off and took it out again for 5 mins to try and see where it was coming from, here are my three possible places but nothing directly leads me to believe it’s any of the three either.
      1. Decompression plug area
      2.  Valve cover gasket leak (not really sure because the amount of oil leaking Looks to be a large amount
      3. Oil tank (bad weld or cracked weld somewhere
      what are you guys thinking?
    • By bofar
      Hey guys. I could really use your help diagnosing an issue that came up riding today. Bike is a 2013 YZ450F. Well maintained and haven't had any issues until now. Both the oil and coolant are new and levels are to spec. 
      After riding for about an hour in the sand dunes, I noticed a grinding going on on the right side of the bottom end (from what I could tell). When I looked to see what was going on my kickstarter was vibrating and grinding really loud. This was a different sound than if you engaged the kickstarter while running. It sounded less "clanky" and more "vibrating/grinding" if that makes sense. Grabbing the kickstarter and moving it didn't help the issue.
      When I noticed it, I shut the bike off and gave it a second. Being a few miles deep into the dunes, I had to get it out of there so I started it back up and it seemed fine- no grinding. I headed back to the car and after a few minutes, it came back so I shut it off again, started it back up and nothing. That process happened one or two more times before I made it back to the truck. Seemed to run fine otherwise. 
      Once I got it back to the truck I started it up and tried to pay more attention to what was going on but it wasn't doing it. I did seem to have more of a metal on metal noise coming from the motor. I started and stopped the bike a few times and after the motor stopped there was a distinct metal clank/grinding noise that happened right after the motor shut of for maybe half a second. This doesn't happen every time. 
      I tried doing some research and have seen things that make me think it could be the spring that connects to the kickstarter, or the kickstarter stopper plate- but really I have no idea.
      Seems strange that the issue is off and on.
      Thanks for the help!
    • By Goof331
      Does anyone know if there is any differences between the 2 radiators? Will the yz450fx radiator bolt on a yz450f? What I am wanting to do is wire up a fan to my 2016 yz450f. I know how I am going to do it I just don’t want to use a “universal” fan kit. What I would like to do is get a 450fx radiator and the direct bolt on Trail Tech fan for that radiator to have a good clean look.