SERVICE INFORMATION
SRM-510ES
8
2-3 Adjusting carburettor
1. Start and warm engine for 1 minute engine
speed at WOT.
NOTE :
If the engine doesn’t start, turn Idle mixture
needle anticlockwise in 1/2 turn increments.
2. Adjust Idle mixture needle (D) to reach maxi-
mum idle speed with 2.5 mm blade screwdriver (J).
3. Set idle speed to 3,500 r/min by turning Idle
adjust screw (E). Engine speed should be stable at
3,500 +/- 50 r/min.
4. Turn Idle mixture needle (D) anticlockwise to reduce
engine idle speed 750 r/min to set idle speed at 2,750
r/min. The idle speed range is 2,700 - 2,800 r/min.
NOTE :
Engine speed must be allowed to stabilize
a minimum of 20 seconds after each adjustment of
idle mixture needle to assure accurate tachometer
readings.
5. Adjust Hi speed mixture needle (G) to reach
maximum WOT engine speed after 20 seconds at
WOT. Then turn Hi speed mixture needle (G) anti-
clockwise to reduce WOT engine speed 120 r/min
(RANG : 100-140 r/min).
Max. approx. 8,000 r/min
NOTE :
Nylon line length should be 225 mm with-
out shield.
6. SRM-510ES(L) : Stop engine, reinstall shield
and restart engine again and verify engine idle
speed ranges from 2,500 to 3,000 r/min, and WOT
engine speed ranges from 9,500 to 11,000 r/min
after 60 seconds at WOT.
NOTE :
Nylon line length should be 160 mm with
shield.
SRM-510ES(U) : Stop engine, Reinstall shield
for blade and 3-tooth blade (255 mm). Start engine
again and verify engine idle speed ranges from
2,500 to 3,000 r/min, and WOT engine speed rang-
es from 11,000 to 11,700 r/min after 20 seconds at
WOT.
Make sure the nylon line cutter/3-tooth blade(255
mm) does not rotate when engine is idle, and en-
gine should accelerate smoothly.
7. After adjusting carburettor, insert and secure new
plug(s) (H) A259-000000 deep in the needle holes
per the Emission Directive using limiter plug tool (C).
NOTE :
Engine WOT, and idle speed in
fi
eld oper-
ation may vary from
fi
nal adjustment speci
fi
cations
due to changing ambient conditions, fuel, and en-
gine loads. Safe engine r/min variances should be
within the safe ranges for WOT and Idling speed
as listed in Section 1-2, otherwise the carburettor
should be readjusted.
ECHO
ECHO
(D)
(G)
(E)
(C)
(H)
(H)
(C)
(J)
(J)
