Yamaha YFZ 450 "S", 04-09

Naumes Oregon Motorsports - Medford, OR

Factory Products Available

Keihin FCR
emulsion tubes

by F Pro

Factory Pro's HDJ emulsion tubes for mx type, original equipment FCR carbs.
Aftermarket horizontal  FCR carbs

also avail
Downdraft  FCR carbs
Replaces the original  worn, overrich FCR emulsion tube. Makes more power and improves throttle response.

On a test yz250f, we gained 5% to 7% hp at peak and better part throttle.

The FCR secret.

FCR emu tubes

28, 31, 33, 35, 37,39,41mm

for HORIZONTAL mount  fcr

pn: CRZ-EMU-125k / 036

for orig equipment horizontal mx type Keihin FCR carbs
also for  aftermarket horizontal FCR carbs.

$79.95 each

1. Choose your shipping method


Item Description

only for yfz450 04-09


Adds more low-end / midrange, if the proper main jet is selected, more top-end power. Easy to install and tune.

 Dec 3 2007, 08:37 PM

Group: Members
Posts: 7
Joined: 29-October 07
From: Henderson, NV
Member No.: 2277

I picked up a Factory Pro Jet Kit from www.factorypro.com

They are a little pricey but WELL WORTH IT! My buddy highly recommended them and I do too now.

Im not sure about all kits, but on my YFZ450 it was a little more than a simple jet kit. I had to drill my factory MAJ and add another MAJ (Main Air Jet). It was incredible and comes with everything you need. It uses the same jet sizes as the GYTR kit however you don't need as large of jets because of the MAJ modification.



Factory Pro's Shift STAR kit - help prevent missed shifts and damage caused by missed shifts.

detent_arm_3XK-426.jpg (15245 bytes) 

Pro Shift Kit

 pn: SHFT-PRO-Y46
(arm and spring kit)


(inc F-Pro Hybrid Ceramic Microbearing Detent Arm & spring)
replaces  3XK-18140-00 arm

 will fit
yz450f 03-05
wr450f 03-06
yz426f 00-02
wr426f 01-02
yz400f 98-99
yfz450 "S"  04-09

z95-004-0601  F-Pro Shift Spring
replaces 90508-26561 stock spring
will fit
yz450f 03-05
wr450f 03-06
yz426f 00-02
wr426f 01-02
yz400f 98-99
yfz450 "S" 04-09
1. Choose your shipping method

The One, the Only, the Classic

Pro Shift Kit

Stage 2 kit.

Virtually eliminate missed shifts.

SLICK rolling Microbearing - almost friction free roller and sturdy F-Pro Shift spring .

Major improvement in reducing missed shifts and improving shift speed.

Takes about an hour to install (right under the clutch basket)

Well I finally got to ride it this weekend with the new shift star, and wow what a difference it makes. I refuse to believe that some time on a grinder with the stock star could make shifting as nice as this piece. I couldn't miss shift if I tried with this thing. It hit every gear every time. and it did it retarded fast, I would say that in one day alone my shifts got 25% faster, and I know that I could get even more efficient. This shift star also got rid of some of the clunky feeling of the stock shifter. The stock one used to feel like it would catch and then clunk into gear, this one just slips right in, I would say that it is worth the investment 100%!!

Evo Shift STAR

The EVO Shift STAR kit will upgrade your bike to the latest, greatest shift action.

Perfect for when you are tired of paying attention to shifting and just want it to shift right. MX. SM, Desert,  trail -

Virtually eliminate missed shifts  - decreases shift process 5mm to 15ms (must re-set shift kill duration if using a Quickshifter)

Make shifting MUCH quicker and virtually eliminate missed shifts. Helps address missed shifts caused by poor shift detent "star" profile.
Helps prevent shift fork and gear engagement dog damage caused by missed shifts.

The Factory Pro Shift STAR kit is an awesome upgrade for the Yamaha.

Installation: Slightly more complicated than replacing the clutch basket.

No case splitting required.

Installation Instructions - click here


Yamaha Shift Star kit worked awesome!  Not one missed shift all weekend.  Easier to find neutral, too - Which is good because I have to put it in neutral to start it for some reason. Doesn't like to start with the clutch in. With the close ratio tranny, I did a lot of shifting.

Leigh Thomas - Mojave area

yfz450 04-09
SHFT-EVO-Y45- star only    $149.95
(Evo Shift STAR only)
replaces 4EW-18185-00 star

fits all
yfm7r 06-12
yfm660r 01-05
yfz450 "S"  04-09
yz450f 03-05 *
wr450f 03-06 *
yz426f 00-02 *
wr426f 01-02 *
yz400f 98-99 *

415 883-5620

1. Choose your shipping method.

Stage 2

Evo shift star

Factory Pro designed Shift Star for error free shifting - Virtually eliminates Missed Shifts and false neutrals and internal damage to dogs and forks caused by missed shifts. 

use after Stage 1 kit

TL-float height gauge   $59.95

The only way to accurately measure float heights. Works on nearly every carburetor.


Tuning Hints



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Contact Factory Pro
M-F, 9am - 5pm, Pacific time, -7 or -8 GMT

800 869-0497
 USA and Canada

415 883-5620

no fax

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