Does anyone know the individual gear ratios inside the transmission for the Yamaha WR 450, both the quad versions and the bike versions? Also primary and secondary gear reductions if any and what their ratios they are?

jason

Will advise when we get back to Melbourne next week.

Cheers

This seems to have the info required:

http://yz450f.yme.com/pages/default.htm

Ben

Here's the spec's from that site.

Type
Liquid cooled, 4-stroke, single cylinder, DOHC 5 valves
Displacement 449 cm3
Bore and Stroke 95.0 x 63.4 mm
Compression ratio 12.5:1
Max. Power N.A.
Max. Torque N.A.
Lubrication Dry sump
Fuel supply Carburettor (FCR39H)
Clutch type Wet, multiple disc
Ignition C.D.I.
Starting system Kick
Transmission Constant mesh, 4 speed
Final transmission Chain
Gear ratio 1 1.929
Gear ratio 2 1.563
Gear ratio 3 1.278
Gear ratio 4 1.05
Primary reduction ratio 2.818
Secundary reduction ratio 3.357

Um...there's one really important thing that this engine seems to be lacking. Anybody?

Maybe the quad version has it?

quote:

---

Um...there's one really important thing that this engine seems to be lacking. Anybody?

---

If you're talking about an electric starter, the wr450f engine has it, but the yz450f does not. The wr450f also has a 5th gear.

The WR electric start bolts onto the YZ engine, from what I can see, but you need the WR rotor cover casing and a few gears and stuff - could be quite expensive.

The WR450 is a five speed, and I think the YFZ450 ATV is as well, but from the parts listings I have they are different gear ratios. I'll check all this when I get home, probably Monday next week.

Cheers all

Anyone got a dyno chart for it? I looked around on the net a bit and couldn't find one.

Here's a "half throttle" run off this website:
http://www.cyclecost.com/shopping/powernow/power_now_dyno.htm



You could scale it up to whatever you expect the peak power to be. YMMV

Also, it's a CRF 450, I don't have a clue how that compares to the WR450.

Wasn't somebody getting ~70 hp out one of these engines...seems like a great hp/weight ratio!
How much do these weigh? I think the F4i weighs in at 120lbs, can't remember if this was wet or dry. Anybody got a torque curve to share?
Also, Is the WR450 a dirt bike?

quote:

---

Originally posted by Clay Corbett:

quote:

---

Um...there's one really important thing that this engine seems to be lacking. Anybody?

---

If you're talking about an electric starter, the wr450f engine has it, but the yz450f does not. The wr450f also has a 5th gear.

---

I'm assuming that if the YZ450F doesn't have an electric starter, the CDI ignition is magneto driven rather than running off the battery?

Ben

thanks for the help.

jason

We urgently need CAD model and manual of Yamaha WR 450.
If you can help please mail me at dcemech89@gmail.com