emuwr3.jpg (9351 bytes)

This is enough wear to make a bike impossible to tune -
Poor mileage and rough">

emuwr3.jpg (9351 bytes)

This is enough wear to make a bike impossible to tune -
Poor mileage and rough, rich running is the result

Worn out NON-REPLACEABLE needle jets?
You need to buy new carbs????

Mileage 1/3 worse than original? Needle jet orifice looks like an egg?

For much less than the cost of new carburetors - Factory Pro will replace your original, worn out needle jets with the brand new, better than original design, patented "HDJ" fuel delivery system.

Proven in many, many VL1500's in 2002 through 2005 - The Factory Pro HDJ System not only provides the correct amount of fuel, but, delivers the fuel in a much more atomized state -  Tested with Belgarda Yamaha on the World Supersport circuit -

The patented "HDJ"  Fuel System allows the engine to extract even more power out of the same amount of air and fuel - simply because the smaller the fuel droplets, the more fuel will born - the more power is produced!  (OK - it's not like it's 10% power - it's more like 1%-2% power improvement - but - it's cleaner and can be jetted even leaner without lean misfire for best mileage w/o surging.)

We rebuild normally non-replaceable needle jet carbs at Factory Pro in San Rafael, CA on the following carbs.



Make

location carb type Rebuild Service Available needle type User replaceable needle jet
part number
cost
Honda            
cbr600f2, all years
cbr600f3, all years
cbr900rr, 93-99
possible more - inc. NT650 and more
all countries   needle jet rebuild rebuild service H21-04
HXX-02 to 05
  $340 + S&H
             
Kawasaki            
zx7r, 96-03 all countries   needle jet rebuild rebuild service K67-07   $340 + S&H
zx9r, 94-97,98-99 and 02 all countries   needle jet rebuild rebuild service K67-09   $340 + S&H
             
Suzuki            
vl1500lc, all years all countries   needle jet rebuild rebuild service - HDJ Style S77-07-HDJ   $280 + S&H

Rebuild Service Turnaround:
Allow 5-7 working days for regular service.
Rush 2 working day service, add $40.

Packaging:
Pack carefully!!! It's best to assume that the carbs will be dropped onto the surface of Mars and are supposed to bounce around for a while before opening!!!!
3"- 4" thickness of  "bubble wrap" around the carbs works pretty well - 
Do NOT throw loose carbs in a box on "peanuts" - they will be bent when we get them!! 
Be careful - Remove any loose parts, like idle adjusters and cables and cable clamps before shipping.

Insurance:
Insure carbs for full retail value + whatever else you can think of.

Shipping:
Ship either "Overnight" or "Second Day".
The less time that the carbs are in transit, the less the chance of damage or loss.


 



 Mikuni 36mm carbs


This is an emulsion tube, (of which includes the needle jet) from a 36mm Mikuni carburetor.
There are basically 2 types:
The set for 3mm (.118") series needles and the  set for 2.5mm (.098) needles.

 Mikuni 36mm carbs


IDENTIFICATION

FactoryPro replacement number fits Mikuni size markings
100102k1221 3mm series needle Y-0, Y-2, Y-4, Y-5
100102k 2.5mm series needle O-6, O-8
"Square in a square"
This is the official Mikuni stamping.
It is on almost every jet that Mikuni makes.

 

Also, we can make larger needle jets upon request.

 

Note!
If you are replacing worn needle jets (emulsion tubes) and the tubes have no markings on them, they are probably dynojet tubes and they will not work with normal needles.

emuwr3.jpg (9351 bytes)

This is a worn 38mm Mik needle jet - It doesn't take too much to make a big difference!

This is a picture of the WORN needle jet area of an emulsion tube from a stock 38mm CV Mikuni carb as installed on Ducati,  Yamaha XTZ/TDM/TRX 850, YZF750, FZR/YZF1000, etc..
It has approximately ~5000 miles or  8000k usage.
Notice that the center hole is noticeably worn at the "V", the 12 o'clock position, which would be towards the engine, as installed in the carburetor.
This causes 2 conditions. First, it allows more fuel to enter the carburetor, as in using a needle with a small base diameter AND the fuel that enters the carb - it enters in larger droplets, resulting in poor combustion.
We carefully check needle jet condition on the vehicles when we create and install carb recalibration kits.
If you install a kit and it is much too rich at low rpm, and lowering the fuel level 1mm doesn't fix it, check the needle jets for any wear - it's not uncommon.
Additional:  Eventually, the carb body, where it holds the slide from rattling back and forth will wear out - allowing the slide to rattle and bang the needle into the needle jet orifice - causing accelerated wear.
Example: The original needle jet lasted 5,000 miles. After replacing the worn emulsion tube / needle jet, they only lasted 3,000 miles or less. That's because the slide guide slot in the carb body is worn - not because of the emulsion tube or needle is bad.
Note! Be famous (for something!)
Have an emulsion tube that's worn? Send it in (in a padded envelope) with make, model, mileage, usual use (in-town, commute or sport), your name and the difference between running before and after replacement. We'll put some of them at the bottom of this page. (08/23/99)

 

Feedback
 

(partial, edited response to FZ1 Owners Group - April 5, 2003)


It a well known FACT that more experienced tuners know that NEEDLE JETS WEAR OUT!!!!!! They wear out on EVERY Japanese CV or slide type carb that has a needle - stock needles, stainless needles, titanium needles, bare 6061 needles and anything else that anybody else has made -

 It's a mileage and usage thing.

The more the mileage - the worse it is -
The bigger the cylinder - the worse rate it is -
The lower the rpm the bike is usually used at - the worse rate it is -
The worst rate are low rpm engines operated at low rpm - as in in-town -
The least worse rate - small engines operated at highway speeds -

It doesn't take a rocket scientist to figure out what happens if they have enough empirical data and a set of carbs in front of them.
The basic problem is that, at low rpm, the intake tract pressure fluctuations simply bang the slide back and forth in the carb's "slide guide" -
That rattles the needle in the bore of the needle jet and just bangs the needle jet, and if the needle is very soft - the needle AND the needle jet just rattle to a slow death - Ya takes your choice - one or both - Titanium seems to be the best choice - esp. over ss.
Mikuni knows that - that's why most CV Mikuni carbs have a step in the slide that spring loads/cocks the needle to one side to discourage deadly needle "rattle".
That's also why Keihin FCR's have actual bearings to keep slide rattle to a minimum (but noisy!) amount - Yep - needle jets STILL wear out in FCR's - and even wear out in the carbs of 250 GP bikes, like RS 250's, TZ250's and Aprilia 250's, too - amazingly enough!
If the slide guide in the less expensive CV carbs didn't wear out - that would make it "less worse" - but as the guide wears - the needle jet wear rate continues to accelerate as that slide rattle increases in amplitude -

We manufacture replacement:
FZR600 needle jets
gsxr / katana 36mm 2.5mm needle jets
gsxr 36mm 3.0mm needle jets
Triumph 900/1200 Mikuni 36mm needle jets
Ducati/TDM/TRX/XTZ 38mm needle jets
YZ/YZF 750/1000 38mm needle jets
FJ1200 needle jets
VL1500 needle jets
RF900/RF600 needle jets
cbr900 needle jets (soon)
Kaw zx900 (and other Kaw models)  needle jets

It would not be cost effective to make all these parts just to fix carbs with a specific brand of needle in them -
In an  informal poll - it looks like our needles were only in maybe 1 in 10 of these carbs - majority were unjetted - with stock needles - and the owner was going to rejet and experienced tuners would catch the wear before trying to jet a set of worn out carbs -

In addition - we are the only people that I know of that have a patent on needle jets that actually make replacement needle jets - We've probably looked at more worn needle jets on more different models than any one single facility in the world - We probably "should" know more than a chat group! Hopefully! :-)

Some wear can be compensated with by fuel level changes and we do specify on the website on models that are prone to wear  to CHECK before jetting -

Open eyes and open minds are terrible things to waste.