Zenoah HC510DV - Manual (Page 17)

8. Operation
In case of restarting immediately after stopping the
engine, pull the starter knob with the choke knob
pushed in (choke open).
4. Push in a decomp valve on right side of the
machine. (OP3)
(1) Decomp valve
In case a starter rope felt to be heavy, check if the
decomp valve is pushed in.
5. Place the machine on stable ground and confirm
that there is no obstacle around the cutter blade.
As in the left Fig., securely hold the machine
with left hand and right foot, and pull the starter
knob. Pull the knob lightly in the beginning and
then hard when it becomes heavy. (OP4)
Do not fully pull out the rope at once or let the knob
go for free return as those may cause failure of the
starter.
6. When initial combustion noise is heard, pull the
throttle lever slightly to return the choke knob to
the first stage position, press the decomp valve,
and pull the starter knob again.
By pulling the starter rope repeatedly with choke
knob pulled out position, the engine may have
difficulty to start due to excess fuel. In case the
engine does not start though the rope is repeatedly
pulled, push in the choke knob and pull the rope
until it starts. Otherwise, remove a spark plug to
dry its electrode, and reassemble. Try again the
starting operation.
7. When the engine is started, lightly pull the
throttle lever and unlock the start setting button.
IMPORTANT
IMPORTANT
NOTE
NOTE
OP4
17 
OP3