ENGINE AT TIMES HARD TO START
PIPISTREL SINUS, Rotax 912UL engine has started first time since new. It has about 600 hours. Last week it failed to start after 5 attempts. After waiting 15 min. it started on the third attempt. Test flight flew fine. The weather was medium hot.
I performed the following:
- gascolator inspected and found clean.
- Fuel flow good.
- Electrical grounds are clean, torqued and marked.
- RPM at ignition starting is between 260 to 300 rpm
- Battery was bench tested by supplier to “like new conditions”
- K&N Air filters freshly cleaned and oiled
- Inspected spark plugs. Gap was good. No wear. Velvet black as usual, resulting from taxing and gliding approaches and landings, Usually using low rpm.
- Balanced carburetors statically and dynamically. They where pretty good.
- I checked that the throttle & choke fully close.
- Fuel is fresh
Engine started first time for about a week. With flights nearly twice a day. Yesterday it required 3 attempts to start. Test flight afterwords was good. (Once it starts it never sounds or smells flooded and runs smooth)
It now appears to be an intermittent problem. Once it starts, it runs very well. The Sinus is a Motorglider. I rely on my motor to start in flight ofter. I am concerned that the next soaring flight might result in a field landing.
ANY ADVICE?
Should I send my Electronic Modules to be bench tested next?
Thank you in advance
Gino
