Mikuni Keihin Hitachi home
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Keihin (it's "kayheen" with accent on second syllable )

Factory Pro Replica jets, Keihin and Mikuni, follow the original manufacturer's size scale so the Factory Pro Replica jets are interchangeable with original jets - saving a lot of time and improving accuracy for a good tuner.

Keihin Pilot jets
(aka "slow jets") Keihin



 

yzf600 R6, 00-01 zx9r, KTM 950

n424-74c-xxx 
F-Pro k type Pilot Jets

$5.95ea
Buy now 4 pc pack / $23.80

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2. Choose your size
Size you want. 

3. Add to cart

(415) 491-5920

Keihin

n424-74c-xxx
5.0mm diameter Slot head
28mm Length


yzf600 R6

00-01 zx9r

KTM 950

Keihin style Pilot Jets

 
Keihin

21 series

 

OEM Honda CV carbs

We either have OEM or we make Factory Pro replicas

Call 800 869-0497 to buy
Keihin

22 series

  We have OEM Keihin Call 800 869-0497 to buy
Keihin

25 series

5.5mm diameter Slot head
15mm Length


OEM Kaw CV carbs
FCR "Flatslides"

We either have OEM or we make replicas

Call 800 869-0497 to buy
Keihin

26 series

5.0mm Slot head
22.5mm Length
OEM Honda dirt bikes w/ CV carbs +

We have OEM

Call 800 869-0497 to buy
 
Main jets, Keihin
( say "Kayheen")
  Keihin

393 series

"Kayheen"
Known as: "Keihin small, round, slotted jets"

5 x .8 thread

most OEM CV carbs

We have:
50 to 250 (larger than Keihin's 225!)

Call 800 869-0497 to buy
  Keihin

357 series

"Kayheen"
Known as: "Keihin long hex jets"

5 x .8 thread

almost every FCR and CRS Smoothbore or Flatslide carb

Call 800 869-0497 to buy
  Keihin

806 series 

"Kayheen"
Known as:"Keihin Harley jets"

6 x 1.0 thread

fits original HD Keihin CV carbs Call 800 869-0497 to buy

\Identify emulsion tubes and needle jets, Mikuni

Identify Yamaha Virago emulsion tubes and needle jets

Identify Honda VTR1000 emulsion tube / needle jet front and rear

FCR needles

Keihin
FCR Flatslide needles
415 491 5920
    FCR only I got really tired of trying to use the original Keihin numbering / profile codes, so I made my own.
Very nice if you have everything perfect at every throttle position except for 1/4 and only want to change that 1 thing! 
Flatslides are super easy to tune on the EC997 dynos and not easy on anything else for many different reasons.

needle shims

 

Emulsion Tubes

Keihin FCR
emulsion tube

by F Pro

Factory Pro's HDJ emulsion tubes for mx type, original equipment FCR carbs. Not for aftermarket FCR carbs.
Replaces original  FCR emulsion tube. Makes more power and improves throttle response.

On a test yz250f, we gained 5% to 7% hp at peak.

The FCR secret.

fits Yam, Hon, Suz, Kaw, KTM and others with 49.5mm stock tubes.
http://www.ktmatvhq.com/forum/attachments/ktmavhq-part-reviews/6909d1356827123-fcr-emulsion-tubes-1.jpg

oem and F-Pro FCR tubes are 49.5mm long


pn: CRZ-EMU-125k

for orig equipment mx type Keihin FCR carbs.
Not for aftermarket FCR carbs.

$79.95 each

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2.
   

 

Emulsion Tubes, HDJ

emutube2.gif (588470 bytes)

note the fuel droplets at the backside of the needle.

emuhidisp.gif (281690 bytes)

note the white spray at the backside of the needle.

patented High Dispersal Jet System
HDJ

 available for licensing
Easily retrofitable in many OEM Keihin, Mikuni and aftermarket carbs and simple to make minor modifications in manufacturing process to incorporate.
Significantly better fuel atomization, runs without misfire at leaner fuel delivery rates, better power from the same amount of fuel, more consistent, smooth running, as verified on
EC997 Low Inertia dyne FLUX value engine smoothness testing. I can explain that if you are not using that dyne system and cannot get that data.
All what an MJN promised, but it can run cleanly at all rpms and, because it still used a tapered needle, is easy to tune properly.

main jets

Main Jets

STYLE Slang.... Where usually used Notes
"Keihin style"
mfg by Factory Pro.
Uses the same number size scale as original Keihin jets.
393 Series
(5x.8 thread)
Commonly known as:
"Small, round, slotted"
used in original equipment CV carbs on Honda, Kawasaki, Keihin equipped Triumph and some Yamaha Range:
 We make larger upper range and lower smaller range than usually available from importers:

#50-#200 in 2.5 increments:
#205 to #250 in 5 increments
"Keihin style"
mfg by Factory Pro.
Uses the same number size scale as original Keihin jets.
806 Series
(6x1.00 thread)
Commonly known as:
"the big thread, round jets for the HD"
Used only in original HD and some European 94-97 ZX9 carbs as far as I can tell. Range: larger upper range

#160 to #200 in 2.5 increments
#205 to #250 in #5 increments

"Keihin style"
mfg by Factory Pro.
Uses the same number size scale as original Keihin jets.
357
"Hex" Series
5 x .8 thread
Commonly called "Keihin Hex jets" Used in most Keihin FCR's, Smoothbores and some dirt bikes.  

carb tools

Mikuni Needle Jets / Emulsion Tubes

UNDER CONSTRUCTION!!!!

 

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