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ORDER: 800-998-3529
TECH: 310-637-8330
The needle jet is the main fuel passage to the main bore (venturi) of the
Mikuni carburetor. Depending on the inside diameter of a specific needle
jet, this will also effect the function of the needle. Therefore, needle
jets and jet needles act together as the main system in controlling the
amount and mixture of the fuel which is drawn in mid-range (1/4 - 3/4)
throttle operation.
On the following application chart, it is noted that certain needle jets
require a specific type of main jet because there are two types of main
jets (4/042 Large Hex & N100.604 Large Round) that have different fuel
flow rate characteristics. Also, needle jets are available not only
in types, but series and sizes. Mikuni series numbers for style of the
needle jet. There sizes (inside diameter size) within each series are
listed according to a letter-number combination.
The letter shows the inside diameter size in increments of .050mm. For
example, the difference between P-2 and Q-2 is that the inside
diameter of needle jet size Q-2 is .050mm greater than P-2.
The number shows the inside diameter size in increments of .005mm
For example, the difference between P-2 and P-4 is that the inside
diameter of needle jet size P-4 is .01mm greater than P-2.
Exception:
(-5) is measured as an increment increase of .005mm. For
example, the difference between P-4 and P-5 is that the inside diameter
of needle jet size P-5 is .005mm greater then P-4.
Lean to Rich
Chart
Size
N-0
Lean
N-2
N-4
N-6
N-8
O-0
O-2
O-4
O-5
O-6
O-8
P-0
P-2
P-4
P-5
P-6
P-8
Q-0
Q-2
Q-4
Q-5
Q-6
Q-8
R-0
R-2
R-4
R-6
Rich
Series
Size
Type Carb Application
159
N-4 thru R-8 P
VM30 - VM36mm Spigot
166(=480)
O-0 thru R-8 P
VM38mm Spigot
169(=172)
O-0 thru R-8 P
VM28 - VM30mm small body
171
N-0 thru Q-8 P
VM30mm Flange
175
N-0 thru Q-8 B
VM28mm Spigot, TM28 Flat
176(=270)
N-0 thru Q-8 B
VM30 - VM36mm Spigot
182
N-0 thru Q-8 P
VM26mm Spigot
183
N-0 thru Q-8 B
188
O-2 thru P-8 P
VM32 Flange, Kawasaki
192
N-0 thru Q-8 P
VM26 Flange
193
N-0 thru Q-8 P
VM24 Flange
196
O-0 thru Q-5 P
205
O-0 thru Q8 P
VM34mm Flange
211
N-0 thru Q-8 P
Kawasaki KR250/350/750
224
Z-0 thru CC-5 P
VM40 - VM44mm Spigot
247
P & Q only
P
Yamaha early YZ250, YZ400, IT400
247
P-0 thru R-8 P
258
O & P only
B
Kawasaki KZ650/1000 w/VM carbs,
Suzuki DR, SP, GS550,GS750/850
Yamaha SR500, TT500, XT500
258
O-0 thru P-8 B
261
0-2 thru P-8 B
VM29 & VM33 Smoothbore
332
O-0 only
B
VM26-606 with side choke, Flange
389
Q-0 thru R-8 P
TM32, 34, 36, 38, 41 Pro & Flat Slide
454
P-8 thru Q-0 B
TM24 Flat Slide
499
P-2 thru Q-4 B
TM33 Flat Slide
568
O-6 thru P-8 P
RS34, RS36, TM36
568
Y-O thru Z-6 P
RS38 - RS40, HS40, TM40
633
S-4 thru S-9 P
OEM TMX (Late Style)
Note: 633 Series not shown in chart, see page 191.
640
P-4 thru Q-2 B
TM33-8012 Flat Slide, Pumper
723
Y-2 thru Z-0 P
HSR42-48 Roller Flat Slide
Note:
Letters Z, AA, BB and CC
are sizes in increments of .050mm.
Numbers 0 and 5 are sizes in
increments of .025mm.
Size
#224
(VM44/10)
Series
Lean
Z-0
003-495
Z-5
003-496
AA-0
003-497
AA-5
003-498
BB-0
003-499
BB-5
003-500
CC-0
003-501
CC-5
003-502
Rich
Two Basic Types of Needle Jets
Size -0
-1
-2
-3
-4
-5
-6
-7
-8
-9
N
2.550 2.555 2.560 2.565 2.570 2.575 2.580 2.585 2.590 2.595
O
2.600 2.605 2.610 2.616 2.620 2.625 2.630 2.635 2.640 2.645
P
2.650 2.655 2.660 2.665 2.670 2.675 2.680 2.686 2.690 2.695
Q
2.700 2.705 2.710 2.715 2.720 2.725 2.730 2.735 2.740 2.745
Size
723
Series
Lean
Y-2
003-685
Y-4
003-686
Y-6
003-687
Y-8
003-688
Z-0
003-689
Rich
“P”
“B”
Primary Choke Type
Bleed Type
Primary Type
Bleed Type
Needle Jets
Needle Jets
Needle Jet Series
224 Series Needle Jet
723 Series Needle Jet
Needle Jet Orifice Diameters
Needle Jets