How to Troubleshoot your model airplane engine
Below is an easy to read table on how to troubleshoot your model airplane engine. Also see our guide on How to Tune Your Engine.
Symptom |
Diagnosis |
Fix |
Engine Does not Fire |
Prop flipped too weakly |
Flip prop vigorously |
Battery low |
Charge battery |
|
Glowplug burned out |
Replace plug |
|
Battery wires faulty |
Replace wires |
|
Engine flooded |
Remove plug, rotate prop to remove fuel |
|
Engine not primed |
See how to start . |
|
Engine fires intermittently |
Battery voltage problem |
Check recommended voltage |
Too much priming |
Disconnect battery and wait a few minutes. If still unsuccessful, Remove plug, rotate prop to remove fuel |
|
Prop flipped too weakly |
Flip prop vigorously |
|
Engine starts, then rpm decreases till engine cuts out |
Fuel mixture too rich (too much fuel) |
Close needle valve half a turn, then restart. |
Engine starts, then rpm increases till engine cuts out |
Fuel not reaching engine |
Check for: a) fuel in tank b) fuel tubing not cut or kinked c) carburetor not clogged with dirt |
Engine starts, then stops as soon as battery wires are disconnected |
Fuel mixture too rich (too much fuel) |
Close the needle valve a small amount |
Glowplug incompatible with fuel used |
Change plug type or fuel type |