Yamaha MZ250 2012, Supplementary Service Manual, Page: 27 / 42

4-6
SPEC
Model name: MZ250 MZ300
Model code number:
7KBJ 7KBN 7VBJ 7VBN
Valve spring: mm (in)
Free length IN
36.2 (1.4252)
EX 36.2 (1.4252)
<Limit> IN
34.39 (1.3539)
EX
34.39 (1.3539)
Installed length IN
29 (1.1417)
EX
29 (1.1417)
Installed compression spring force
IN N (kgf, lbf) 91.20–104.93 (9.30–10.70, 20.50–23.59)
EX N (kgf, lbf)
91.20–104.93 (9.30–10.70, 20.50–23.59)
Tilt limit mm (in)
1.7 (0.0669)
Carburetor: mm (in)
Type/manufacture
BV24-18/MIKUNI
I.D. mark
7KB00 7VB00
7VB00
7VB10*
Bore size
ø18
Main jet
#96.3 #103.8
Main air jet
ø1.7 (0.067)
ø1.85
(0.073)
ø1.85 (0.073)
ø1.8 (0.071)*
Pilot air jet
ø0.8 (0.032) ø1.0 (0.039)
Pilot outlet
ø1.1 (0.043) ø1.0 (0.039)
Valve seat size
ø1.5
Main nozzle 62B 60A
Pilot jet
#37.5 #45
Pilot screw
2 turns out
Throttle valve
#120 #125
Governor arm:
Tension spring attach hole
2 8 2
Engine speed: r/min
High engine speed
3750–3850 3700–3800 3750–3850 3700–3800
Low engine speed
1900–2100 — 1900–2100 —
* MZ300KHIDM
1
2
3
4
5
6
7
8
9
MAINTENANCE SPECIFICATIONS