Intermittent Starting Problem
in 912 / 914 Technical Questions
6 years ago
I have a 912 ULS with 65 hours and a 1 month old PC680 battery. I replaced the battery thinking it was the cause of the problem. After replacing the battery, the engine started a couple of times with no problem.
On a couple of subsequent tries to start the engine, the prop/engine would rotate 1/4 to 1/2 revolution and stop. I've checked connections, voltages and resistances in the starting circuit with no obvious problem. The starter solenoid is functioning properly. I'm getting 10.7 - 10.8 volts at the battery when cranking which I understand is ok.
To check the starter, I disconnected it from the battery with the ignition switch off and jumpered it to a car battery. With the car battery. the prop/engine rotated at a speed that would have started the engine if the ignition was on. So the starter seems ok. After disconnecting the car battery and reconnecting the plane battery, the engine started with no problem. A couple of days later, the engine started easily and I flew for an hour. Today, one week later, the engine again would not start with the prop/engine rotating 1/4 to 1/2 revolution and stopping. I've been keeping the battery on a smart charger during this period.
Any suggestions on what the problem might be or other ways to troubleshoot? Do Rotax starters have an issue with intermittent failure? We have had quite a bit of wet weather and although the plane is hangered, some water does get on the floor. Could this be a factor?
Thanks in advance. Rich
On a couple of subsequent tries to start the engine, the prop/engine would rotate 1/4 to 1/2 revolution and stop. I've checked connections, voltages and resistances in the starting circuit with no obvious problem. The starter solenoid is functioning properly. I'm getting 10.7 - 10.8 volts at the battery when cranking which I understand is ok.
To check the starter, I disconnected it from the battery with the ignition switch off and jumpered it to a car battery. With the car battery. the prop/engine rotated at a speed that would have started the engine if the ignition was on. So the starter seems ok. After disconnecting the car battery and reconnecting the plane battery, the engine started with no problem. A couple of days later, the engine started easily and I flew for an hour. Today, one week later, the engine again would not start with the prop/engine rotating 1/4 to 1/2 revolution and stopping. I've been keeping the battery on a smart charger during this period.
Any suggestions on what the problem might be or other ways to troubleshoot? Do Rotax starters have an issue with intermittent failure? We have had quite a bit of wet weather and although the plane is hangered, some water does get on the floor. Could this be a factor?
Thanks in advance. Rich
