Design Symbols Used On Ngk Spark Plugs - BOMBARDIER 1996 Ski-doo MX Z440 Handbook

Section 04 ENGINE PREPARATION

DESIGN SYMBOLS USED ON NGK SPARK PLUGS

First letter prefix for thread
and hexagon size
Letter Thread size Hexagon
size
25.4
mm
A 18 mm
B 14 mm 20.6 mm
c
10 mm 16.0 mm
18.0 mm
D 12 mm
F 7/8 in-18
23.8 mm
G PF 1/2 in-14
B PI 6 E s
04-98
Second and third letter prefix Heat rating number
for construction feature,
except single prefix
Letter Construction feature 2
B Hexagon size 20.6 mm
c
Hexagon size 16.0 mm
Hexagon size 23.8 mm
G
6
L Compact type (SHORTY)
7
M Compact type (BANTAM)
P Projected ineulator
8
nose type
R Resistor type
9
s
Shielded type
u
Surface dkcharge type 10
11
12
13 Coder type
14
First letter suffix for thread:
reach
Hotter type Letter
Thread reach
12,0 mm
(thread dia. 18 mm)
None 9.5 mm
(thread dia. 14 mm)
plug
16,0 mm
(thread dia. 7/8 in-18mm)
(85)
11.2 mm
H 12.7 mm
(95)
(racing type IB.O mm)
E 19.0 mm
(racing type 18.0 mm)
(105)
Racing F Conical seat type
plugs
A -F
B - F
BM - F
BE - F
Second letter suffix for con-
Letter Construction feature, etc.
A -Specials
B -Special plug for Honda
vehicles
-Competition type
-Racing plugs, center
electrode of nickel alloy
-Racing plugs, center
GV
metal
N -Racing plugs, nickel
electrode
P -Racing plugs, platinum
ground electrode
R -Shielded resistor plugs
s
-Copper core center
electrode (Super)
v
-Center electrode of
precious metal
w
-Tungsten electrode
x
-Series gap plugs
-V-Grooved center
electrode
10.9 MM
11.2 MM
7.8 MM Multiple ground electrodes type
K 2 T 3
17.5 MM
M 2 Q 4
Others Expect forabove letters,
there are special plugs
of J, L Z, etc
1
Wide gap type (mm)
11