Failed circlip on jet needle
in General Tech Discussion
6 years ago
Asking if there have been any reports on a failure of the little circlip holding the main jet needle up in the carb dome.
2 weeks ago after a perfectly normal ignition check & run-up to 3200 rpm ... on the take-off roll ... my 2016 914UL serial # 9575603 (2016) engine with 180 hours on it failed .... ran rough no power ...."shake like a wet dog" would still idle & taxi ... but as soon as rpm above 2200 ... rough & shaking!
After looking for sinking floats & fuel supply issues .... decided to do the 200hr carb service 20 hours early!
Discovered the o ring & circlip on 2/4 main jet needle had vanished ..... 2/3 of circlip was found under the retaining screw ... the rest had gone into the engine ...... heavy rotax mechanic pulled the heads to look for the tiny piece ... verify it was not lodged in the rings or valves! several marks were seen on piston & head ( bead blasted smooth again) ..... it appeared to have gone out into exhaust ... the turbo was also inspected ... no damage on fins verified!
I have filed a CSIR with rotax! I have heard of another circlip failure ..... wondering if more are out there!
I will be replacing circlips at 200 hr carb inspection .. rekits from now on!
This is instant power failure /engine shutdown situation .... I am grateful it happened on the ground & I fly a gyroplane ...which is a great machine to land in small spaces ... although I will suffer great anxiety when flying over hostile landing terrain from now on!
2 weeks ago after a perfectly normal ignition check & run-up to 3200 rpm ... on the take-off roll ... my 2016 914UL serial # 9575603 (2016) engine with 180 hours on it failed .... ran rough no power ...."shake like a wet dog" would still idle & taxi ... but as soon as rpm above 2200 ... rough & shaking!
After looking for sinking floats & fuel supply issues .... decided to do the 200hr carb service 20 hours early!
Discovered the o ring & circlip on 2/4 main jet needle had vanished ..... 2/3 of circlip was found under the retaining screw ... the rest had gone into the engine ...... heavy rotax mechanic pulled the heads to look for the tiny piece ... verify it was not lodged in the rings or valves! several marks were seen on piston & head ( bead blasted smooth again) ..... it appeared to have gone out into exhaust ... the turbo was also inspected ... no damage on fins verified!
I have filed a CSIR with rotax! I have heard of another circlip failure ..... wondering if more are out there!
I will be replacing circlips at 200 hr carb inspection .. rekits from now on!
This is instant power failure /engine shutdown situation .... I am grateful it happened on the ground & I fly a gyroplane ...which is a great machine to land in small spaces ... although I will suffer great anxiety when flying over hostile landing terrain from now on!
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