2014 yz450f First Impression and Dyno test

Hey Guys:

So the new 14's are here as we well know - and I have been lucky enough to get some testing time on them.  I've done quite a bit with the 2010-2013 models with modifications etc...and really liked the engine package the yamaha was capable of, and while it had some handling quirks I really loved the suspension character of the bike once tuned in too.

For the shop four stroke steed we have a kawi 450 just as an FYI.


First things first - the bike is ALL new - yes yamaha is saying that, but believe it.  Even the front axle is different among many other things.

Secondly - the suspension settings in the forks are VERY close to what many of the aftermarket were doing on the previous generation.  It's valved relatively firm up front for a stock bike (surprisingly firm - I think many weekend warriors riders may want it softer)  and the rebound set up has been dramatically changed up front.  It still feels a little tall in the rear - for now we are running it lowered 1.5mm internally.

Now onto the absolutely shocking thing about the bike - the motor.  The 2010-13 yamaha could crank out HP relatively easily when modified.  Throw in some good cams, race fuel pipe and mapping and you had a motor most other brands couldn't touch with more intensive mods.  Add an epoxied and ported head, aftermarket ignition system and a few other tricks and I personally feel NO other 450 was close (maybe ktm).


That said a stock 2010-2013 was about par for the course compared to a kx or a rmz.  I've attached what we dynod the 14 that came into our shop at vs a brand new kawi 450 we ran just a few days prior - first run I didn't believe it and subsequently went through everything on our dyno and ran it a few more times vs a couple other bikes we knew to confirm - but believe it - the motor ROCKS.  The engine dyno's WAS ON fresh VP 4.4, but stock mapping.  The fuel IS worth power, customer brought it with that fuel in tank.  The power indicated in the graph is at the peak power point of the kawi - not the yamaha.  Yamaha made one more peak hp than indicated on the right legend of the chart. Compared to our full blown race package for the 2013 it's down 2 horses but up in peak torque - arguably a faster race engine stock.

On the track it's smooth but VERY fast.  Mapping is a little lean, it pops sometimes.

It's geared very tall in 1 2 and 3. What that does is spread the power over a wider window - makes the bike very easy to ride but masks it's pull.  The kawi on the race track will feel to pull similarly through early gears and out of turns, but for reference on the dyno the kawi ran up to 43MPH at rev limit in second - the yamaha was 50mph!  

If the yamaha were geared to hit the same 43 at the end of 2nd it would probably be un ride-able.  


Lastly dyno's are all different.  Ours is set up to read similarly to MXA - maybe a hair less than them.  


Screenshot (5).pngIMG_2689.JPGIMG_8001.jpeg

Enjoy - After riding it stone stock then with some suspension work - the bike kicks major butt.  I had a few issues catching my boots on the left side rear number plate but I immediately wanted to kick my kawi to the curb after riding the new yamaha.


Edited by harrperf

Pretty impressive numbers. A few comments about horsepower in a recent thread abut the '14 YZ may need to be edited.

How much do you think the different fuel contributed to the numbers?


MXA posted some numbers for the '13 CRF


Peak......52.49 at 8800 rpm stock
Max torque...34.44 stock at 6900 rpm

In the case of most 450 MX engines, U4.4 should be worth at least 1 full HP, probably close to two, depending on the pump gas it's compared to.

Could someone post the stock 2014 stacks...im just curious

Biggest change in the forks - 1mm bleed hole is in the midvalve piston as per models prior to 2010.

That plus use of a much stiffer base valve - of memory it was 12x32.20

So they're shifting the compression damping more toward the base and less to the mid, if I understand correctly?   It would be great to see the stacks listed. 


No crossover in among the 12 32's?

THANK YOU FOR THE POST! I'm on a 12 and ready for the 14... just wanted to get some more info prior to see what I would have to do to get her dialed in just right.

Off topic but here goes.

The yz450f puts out over 55hp stock. Yet the yfz450 doesnt come close. Why dont companies make a atvs as powerful as their 2 wheeled bikes?

Off topic but here goes.

The yz450f puts out over 55hp stock. Yet the yfz450 doesnt come close. Why dont companies make a atvs as powerful as their 2 wheeled bikes?

I don't think it's that they are not making them as powerful but more that the needs are diffrent. Kind of like an LS motor in a truck vs the same motor in a car.

I think alot of people buying quads would end up hurt, not a knock against the serious quad riders but a good portion simply dont wear gear, and lack the skills to ride a 55 hp machine safely

True. But on the other hand, looks how easy it is go get hurt on 2 wheels even with a 250(or 125 2 stroke).


Valid points though. At least if they decide to up the power a tiny amount on the atv's, it's easy for them.


I'm assuming it's all in the head/cam design since displacement is roughly the same.

HARRPERF.   I have the FMF 4.1RCT ti system with a mega bomb header for my '14.  I remember reading in MXA that the bike runs lean with the STOCK pipe, however with the full blown FMF pipe it ran great (with stock ignition/ mapping settings).


I just bought the Yama-tuner for the F.I. settings etc.  


Do you have any knowledge of the maps?  Should I just call FMF and ask them?


I will definitely buy the U4.4 race fuel when I start racing.  (Not like I could even use 30HP of this bike).  LOL

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