Courtesy Honda


CR 80R  91-07
CR 85 03-07

CRF 150R  07-23
CRF 250R 04-08
CRF 250X  04-17

CRF 450 R 02-16
CRF 450 X  05-17

Factory Pro's Shift STAR kit -
help prevent missed shifts and dog and fork damage caused by missed shifts.
(sample pic, not actual H45)



(inc 1 EVO STAR,-arm and spring -  gaskets not supplied)
replaces Stock star
1. Choose your shipping method

crf450r EVO Shift STAR  kit

The Star, Arm and Shift Combo kit

The Factory Pro EVO Shift STAR Upgrade will upgrade your bike to "better than new" quicker, more consistent shift action.

Suggest Star, Arm and Spring for best shifting.

Proven in 15+ years of pro level use.

Virtually eliminate missed shifts.

Help eliminate 5th and 6th ghost neutrals.

Decreases shift process 5mm to 10ms each shift.

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 is an awesome upgrade for the notchy Honda shifting.

Installation: Slightly more complicated than replacing the clutch basket. It's right behind the clutch basket.

No case splitting required.

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

Factory Pro Around the World

Winter in Moscow, 2009


Tech Tips

 Factory Pro's
patented HDJ  MAJ installation for crf / wr / yfz
 Keihin FCR carbs

Where's my main air jet and what do I do with that drill bit and tap that came in my Factory Pro HDJ kit for my Keihin FCR carb?

First step is to eliminate the fixed main air jet restriction.
It's about 40mm down the MAJ hole (left picture).

Set your 3mm drill so that it has 45mm to 46mm of drill bit exposed from your drill chuck.
(see right picture)

Remove the stock emulsion tube (that's what the main jet screws into) so that you can clean out the carb well. By only having 45mm to 46mm of the drill bit exposed, it prevents you from drilling too far.

Then, use the supplied tap from our HDJ carb kit, thread the Main Air Jet (aka "MAJ") hole.
You only need to go far enough to be able to thread in the new replaceable jet that we supply.

Clean the hole, of course.

After it's clean, complete the MAJ Modification by installing the supplied Main Air Jet and installing the new Factory Pro HDJ Emulsion Tube.

If you aren't confident in your ability or in your understanding of what you are trying to accomplish - no worry - Call us up or talk to someone locally who has more experience in these matters.
If you are still not sure, see if there's a
Factory Pro Tuning Center locally or visit your favorite local dealership or shop and get some help there -

We all have to learn, and "usually", having an experienced person around makes everything "easy".

This modification is something similar to what we've done in many different carb types over the years, though it might be new to some who haven't used our "1.7-RK" carb kits before.


Available direct from:


To adjust float height:       Sooo....

You read the carb kit instructions and they specify a 15mm float height. Float height? What's a float height?  15mm? How much is that in inches? (it's .590")

Does that mean I must do it???

Gee whiz!   What do I measure with??

You can use a set of vernier calipers, if you have them - they are great for measuring all sorts of things, but you can make it even easier with our...

Float Level Setting Gauge

Measures from 0mm to more than you will ever need!    Easier to use than vernier calipers on carbs. The vertical legs adjust in width and the thin post slides up and down so you can slide the post to the required clearly marked float height measurement.


Remove float bowl screws. Factory Pro gives you replacement allen screws in most carb kits to replace usual phillips screws.

Slide the lower movable leg so that both legs will rest on what would be called the gasket surface of the carb body (if there was a gasket, anyway)


Tilt the carbs so that the floats just flop over towards and into the carb body.

Tilt just enough to touch and close the float the float valve, but...

Do NOT compress the float valve spring when measuring (only exception is 95-97 zx6r)

Test adjust the "L" horizontal arm in the usual 1mm increments and test fit the guage to see what the float is set at now. (or not).

(If we say 15mm and you measure 4mm less than that - you might be compressing the little float valve spring.)

At this time, you can set the Float Height Guage to what you want to reset the floats to.
If you are tuning, you'd usually use 1mm increments

CV Carbs: Too RICH at full throttle / low rpm (that's the most common in CV carbs)
Slide carbs (FCR's) - Float height controls 25% throttle at ALL rpms.

If the float height is too low (small float height measurement), bend the tab slightly to increase the height measurement. It's a 5:1 movement ratio.

CV: If the float sticks out further, down, into the float bowl, the carb will deliver less fuel (leaner), especially at low rpms and at cruise.
Slide carbs: Float height controls 25% throttle at all rpm's, even at redline.

You'd generally change the float height in 1mm increments when tuning.

It will affect the topend slightly. Maybe 1.5mm leaner float height would require 1 size larger main jet to keep equal main jet fuel delivery.

CV Carbs: Too LEAN at full throttle / low rpm (not too common in CV carbs)
Slide carbs (FCR's) - Float height controls 25% throttle at ALL rpms.

If the float height is too LARGE, bend the tab slightly OUT to decrease the height measurement.

If the float sticks out further, UP, into the carb body, the carb will deliver MORE fuel (richer), especially at CV low rpms and at cruise.

It will affect the topend slightly. Maybe 1.5mm richer float height would require 1 size smaller main jet to keep equal main jet fuel delivery.

You'd generally change the float height in 1mm increments when tuning.

When you are done, a multi-cylinder must be all within .5mm (1/2mm) or .020" range of each other.


Nifty baffle plates in the 05 KLX300!
This carb type has been around since the early 80's! It's had some updates over the years. It's similar to the Ninja 900'a and ex250 styles.
A view from the engine side, butterfly open.

Why adjust the float height?

Changing the float height changes the level of the fuel in the float bowl. The fuel height adjusts the full throttle, 2k-3k rpm and part throttle cruise, as in cruising around town, trying to be quiet... To give a scale of change, if the bike runs well when cold, but gets a bit sloppy when fully warmed up, lower the fuel level 1mm (i.e. go from 15mm to 16mm float height - remember the float measurement is "backwards").

When do I adjust the float height?

When installing a Carb Recalibration Kit tm.
When rebuilding carbs.
To adjust low rpm / part throttle operation that isn't pilot jet, fuel screw or needle height related.
When a bike starts running rich at  low rpm after a mishap or
After an overwhelming gravity equalization process occurs.

How much is the nifty Float Valve Measuring Tool? How much is that nifty Float Valve Measuring Tool?

About $49.95, direct from Factory Pro

415 883-5620

415 492-8803 fax



Absolutely NO carb parts sold in California.

New and improved Suzuki Teka SFI  2

with new TPS display and "MMT" Memory Module Tuner

Finally - Quick, easy, cost effective Suzuki tuning with no expensive "add-on boxes"
Suzuki cruisers and sportbikes

Please click here for more info

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

800 869-0497
 USA and Canada

415 883-5620

parts information

EC997 dynamometer information

Product Support /Tech SECTION
click here


Mailing / Shipping address:

Factory Pro
101c Roblar Drive
Novato, CA

And most importantly
Restart back at the HOME page and click on the red box in the top left to find the bike that you want parts for...
restart at HOME page


This Tuning Site has been visited by
people. - the oldest counting service on the web





EFI and Carb Tuning - Most all FI and carb tuning

by Wheelsmith Racing

Flight Training - train with AMA race winner Todd Harrington.

The Harringtons own American Flyers, one of the most established flight training facilities in the USA.

 8 locations

The Rich Oliver Mystery School will help you discover your hidden inner strength. 
It will challenge you. It will teach you a new way of thinking, and a new way of riding. You can take your riding to an exciting new level!  

We use a variety of proven drills and training techniques. 
Practicing these techniques with our Yamaha dirt track trainers will enhance your abilities both on the track or the street.  

It doesn't matter what you ride or race, the Rich Oliver Mystery School improves everyone's skill level and mindset!

WW2 vintage flying Special

Book a sightseeing flight over the Wine Country or a Kamikaze aerobatic flight or a biplane flight over famous Sonoma Raceway, the Golden Gate Bridge and the San Francisco Bay for one or two during the spring and get a free souvenir t shirt!
(NEW!  Ask about the P-40 flights!)

707 938 2444

Just tell them that you saw this on the Factory Pro website!
Northern California's most unforgettable flying experience.  No experience required.  Open weekends!

The extension of the laboratory for engines of the Swiss Federal Institute of Technology was completed in about 1935. Its architect was Rudolf Otto Salvisberg (1882-1940). He had a successful career in Berlin but returned to Switzerland after the advent of the Nazis. His architectural style was somewhat similar to that of Erich Mendelsohn. The staircase of the laboratory is in normal use but well preserved.
Edited to the tunes of Chemical Residue by Herbie Hancock.