Engine Out

[FlynHigh]

I was flying this morning, after flying for about 35 minuets this is about 7:35am, temp., around 80 degrees and saw a friend and did a tight spiral, rpms between2400 and2600, dropping about 200ft and Generac 33hp quit.
Had enough altitude to try to restart, would not restart. All the time looking for a spot to land. Picked a landing spot and flared it in with a good landing.

After getting plane home looked it over for any damage and found nothing, then tried to start and it turned over quite a few times so pulled chock and it fired right up.

The only thing I can think of is the centrifugal force some way or another caused it to starve for fuel. Maybe Marty or someone else may have some idea of what transpired.

Has any of the other Dragonfly owners had any such problems?

Richard

[Bill Martin]

Carburetor ice maybe? Early morning, high relative humidity, long glide with low rpm. That's a perfect setup for carb ice. When the throttle is closed, vacuum increases in the intake manifold causing temperature in the carb throat to go way down. I've seen it go down as much as 40f below ambient temperature in a rotax. After landing, the ice melts, the engine starts, and you never know for sure what actually happened. Perfect conditions for icing are between 60f and 80f with high humidity. When it's colder, the air is usually too dry to form carb ice. When it,s warmer, the carb and manifold don't get cold enough to freeze. Next time you fly, make a long approach at low RPMs. When you land, Immediately get out and feel the carb body and manifold. You'll be surprised how cold they are even on a warm day. Bing carburetors with slide valves are less susceptible to carb ice than carbs with butterfly valves, but even they get carb ice. (I can personally vouch for that). If you have a Grand Rapids EIS instrument system, you have an option for carb temp. The sensors are about 30 bucks. It's a good investment. Even with no carb heat, you will know when the manifold temps are getting iffy and do something about it. First indications are usually a gradual loss of RPMs, then rough running (but not always), then that Godawful silence.

Bill.

[Dreamer]

Originally Posted by FlynHigh

I was flying this morning, after flying for about 35 minuets this is about 7:35am, temp., around 80 degrees and saw a friend and did a tight spiral, rpms between2400 and2600, dropping about 200ft and Generac 33hp quit.
Had enough altitude to try to restart, would not restart. All the time looking for a spot to land. Picked a landing spot and flared it in with a good landing.

After getting plane home looked it over for any damage and found nothing, then tried to start and it turned over quite a few times so pulled chock and it fired right up.

The only thing I can think of is the centrifugal force some way or another caused it to starve for fuel. Maybe Marty or someone else may have some idea of what transpired.

Has any of the other Dragonfly owners had any such problems?

Richard

Hi FlynHigh: I have had 3 engine outs on my generac, twice within 5 min. The first time I was at 1600 ft. I choked the motor & it started then I had to play with the choke (half choke to 1/4 choke) whatever it took to keep the motor running. It started to run better then quit again within a few minutes. So I did the choke thing again & after a few minutes the motor ran great for 45 min. not missing a beat. About a week later the same thing happened after being airborne 15 min. the choke trick did not work this time & I also had to do an emergency landing. I mentioned this on this forum & Darrell asked about my gas cap,he said some of the dragonfly gas caps are not venting. He also gave a Napa part # for a new cap. I did some work on my original gas cap & have not had any more issues. I would guess I have 50 to 60 hrs. since my last engine out. I do however carry a spare gas cap in my coat pocket. If You have another issue with the motor while flying or running it on the ground try reaching back & open the gas cap to let air in then tighten it again to see if it will run for a little while. After I had these engine outs I noticed that whenever I opened my gas cap I would hear a hiss or hissing sound ( which indicates gas cap not venting). Hope this helps. Dreamer

[FlynHigh]

Thanks Bill and Dreamer,
As I said I was doing a tight spiral that lasted no more than 50-70seconds at a rpm setting of 2400-2600 was not a long decent and the forecast was for lower humidity although I don't know what the humidity reading was as for the gas cap I had changed mine when it was discussed here before. Saying this is not disputing in anyway our comments, just trying to give more information that may help other fliers. Thanks fellows for your reply.

Richard

[John Boy]

Originally Posted by FlynHigh

I was flying this morning, after flying for about 35 minuets this is about 7:35am, temp., around 80 degrees and saw a friend and did a tight spiral, rpms between2400 and2600, dropping about 200ft and Generac 33hp quit.
Had enough altitude to try to restart, would not restart. All the time looking for a spot to land. Picked a landing spot and flared it in with a good landing.

After getting plane home looked it over for any damage and found nothing, then tried to start and it turned over quite a few times so pulled chock and it fired right up.

The only thing I can think of is the centrifugal force some way or another caused it to starve for fuel. Maybe Marty or someone else may have some idea of what transpired.

Has any of the other Dragonfly owners had any such problems?

Richard

how much fuel did you have at the time? if you had less than 1/2 tank and laid it on its side it might have been sucking air because the pick up is in the center, but u would have been making top gun moves for that to happen!!! Also make sure all your fuel lines are tight, mainly the 1 at the carb. so its not sucking air. Set it outside in the sun for awhile then go take the gas cap off and see if you here that hissing. thats all i got for now!! Ha Ha

[FlynHigh]

Originally Posted by John Boy

how much fuel did you have at the time? if you had less than 1/2 tank and laid it on its side it might have been sucking air because the pick up is in the center, but u would have been making top gun moves for that to happen!!! Also make sure all your fuel lines are tight, mainly the 1 at the carb. so its not sucking air. Set it outside in the sun for awhile then go take the gas cap off and see if you here that hissing. thats all i got for now!! Ha Ha

I had topped off the tank after warming up before taking off and had not flown more than thirty- five to forty minuets. Thanks John Boy