O.S. engine max-12TZ series Owner's Instruction Manual page 15

Symptom
Unstable idle
Cause
Unsuitable glowplug
Unsuitable fuel
Extremely light flywheel
Silencer is disconnected or has play
Symptom
Not reaching expected peak r.p.m.
Cause
Insufficient warming up or running-in.
Silencer or manifold is not securely connected
or disconnected.
Fuel tubing from tank is split or broken.
Symptom
Poor response
Cause
Deteriorated glowplug
Incorrect carburetor settings
Incorrect setting of transmitter Exponential function. Check the transmitter setting.
Incorrect linkage
Symptom
Poor r.p.m. drop
Cause
Throttle position open too far.
carburetor not fully seated
Metering needle closed too far.
Corrective action
Use suggested glowplug in the instructions.
Do not use extremely high nitro
or low oil content fuel.
Add suitable load.
Install silencer securely.
Corrective action
Set the needle only after warming up.
Complete running-in.
Replace seal ring.
Check the connections and secure them.
Replace the tubing.
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Corrective action
Replace glowplug.
Readjust low r.p.m. range with metering
needle and mixture control valve.
Make sure that throttle servo does not interfere
servo linkage.
Corrective action
Close metering needle to adequate position
to lower idle r.p.m.
Install carburetor securely.
Open the metering meedle a little.
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