O.S. Engines 91HZ-R - Manual (Page 21)

40
Symptom
Cause Corrective action
Symptom
Cause Corrective action
Unstable idle
Unsuitable glowplug Use suggested glowplug in the instructions.
Unsuitable fuel Do not use extremely high nitro or low oil fuel.
Silencer is disconnected or is loose Install silencer securely.
Not reaching expected peak r.p.m.
Insufficient warming up or running-in.
Set the needle only after warming up.
Complete running-in.
Silencer or manifold is not securely connected
or disconnected.
Check the connections and secure them.
Fuel tubing from tank to is split or broken. Replace the tubing.
41
Symptom
Cause Corrective action
Symptom
Cause Corrective action
Poor response
Deteriorated glowplug Replace glowplug.
Incorrect carburetor settings
Readjust low r.p.m. range with metering
needle and mixture control valve.
Poor r.p.m. drop
Too much throttle opening at idle.
Lower the throttle trim to adequate position
to lower idle r.p.m.
Incorrect carburetor fitting Fit carburetor securely.
Inaccurate linkage
Recheck the throttle opening against
the pitch angle.
Needle-valve closed too far. Open needle-valve slightly