DA-50R - Possible bad hall sensor has anyone seen this?

[Vahn]

After many successful flights on DA-50R on Saturday morning, I came home wanting to do some throttle servo programming to have a more linear range from bottom to top. I was getting max RPMs at about 55% of the throttle (and they were good RPMS, about 7100) and no amount of end point/travel adjust adjustment in the radio was really cutting it.

I use the DX-7, which doesn't have a throttle curve.

Long story short, I couldn't get the engine to start. I tried for several hours on Saturday afternoon and again on Sunday, Monday, and Tuesday.

This is uncharacteristic. Up until this point, including that same Saturday, this DA-50R would pop in about 6, and start in about 4, and would start unchoked the rest of the morning in a flip or three.

So, I go through and eliminate each component as a possible failure:

• Battery voltage is good all the way through the system with or without the switch and regulator.

So, I drag the plane down to Airwild today to get a second opinion:

• We replace the spark plug. Nada.
• We try a different DA-50r Ignition. Nada.
• We double check the ignition power (again).

Finally, we pull the plug and notice we are not getting any spark regardless of the plug and ignition combo when we spin the prop.

The only thing I couldn't try was to replace hall sensor as we would of hand to cannibalize even more parts to do it and Jerry @ Airwild is doing me a favor as it is.

I call DA around 4:00 PST today and Jeff answers. I take him through the entire story. He thinks the Ignition safety / hall sensor has gone bad and promises to UPS me a replacement immediately.

(That's awesome service.)

I'm just curious if anyone else has seen this or has anything else I should try while I wait for a replacement? I checked the current sensor, it doesn't seem to have slipped. The nuts are still tight.

I've gone over everything no less than two dozen times, with and without adult supervision , so I'm at a loss, but at least I (now) know that I am not getting a spark.

I'm hoping it is ignition sensor, and that my ignition module hasn't gone bad.

Based on some other threads here in the support forum it looks like the spark plug cap can fail as well? Anyway I can test that?

This is my first gas engine. So, I'm a newb. Up until this point, I haven't had any issues. The engine is relatively new, but broken in and running Amsoil 100:1.

Posted edited: Ignition safety = Ignition Sensor / Hall Senor

[Greyhoundman]

What an an ignition safety?

Just curious are you referring to the hall sensor....the magnetic pickup that is attached near the base of the prop shaft.

[Bill_Higgins]

	Quote: Originally Posted by Greyhoundman
	What an an ignition safety? Just curious are you referring to the hall sensor....the magnetic pickup that is attached near the base of the prop shaft.

I think I head Jeff talking to Vahn earlier today at work, and I think we are talking about the ignition sensor, but I could be wrong.

Bill Higgins
Desert Aircraft

[Vahn]

Yes. We are talking about the same thing. I edited the post to include the "hall sensor." I hadn't heard it called that before I thought Jeff from DA called it Ignition Safety, but maybe he called it Ignition Sensor.

Thanks for the clarification.

[madmax]

(post title edited per author)

[Vahn]

Fast update - and a lesson in what NOT to do when trying to troubleshoot problems.

This was at least one of the problems. I got the replacement part last night (shipped in 2-days for free) put it on, and I started sparking again with old and new spark plug.

However, I still couldn't get the plane started. I got it pop one time in many many attempts, but never started.

After about the 7th attempt of testing the plug outside the engine and getting spark and putting it back in the engine, but not starting, I had a thought that perhaps I wasn't seating the spark plug in the engine correctly.

I gave it a bit extra torque and SHREDDED the base of the spark plug off. Brilliant eh? Kinda like breaking a light bulb in the socket but 10X worse.

I managed to get what was left of the spark plug out, but the threads are toast.

Fortunately for me, DA is going to take a look at it. I sent it back this morning.

I am a now a big DA-50 fan. I picked them on the strength of reputation over other gas engine manufactures and I'm really glad I did.

Sure, I'm having some problems, but I can't complain. The engine has been great to this point and the service has been excellent.

This latest setback is my own fault.

To Jeff and the guys at DA - thanks a bunch.

[Absolut Yak]

I feel your pain. I smacked my plane in (now flying again) and ripped the firewall off in the process. The engine was restrained by the hall sensor to ignition lead. Rebuilt the plane, put the engine back on, drove 14 hours to Texas to fly with a friend for the weekend and the plane would not start on my initial attempts for it's re-maiden. Long story short, no spark. Took the ignition module off a brand new DA 85 and its hall sensor. Swapped individual components and decided both the ignition and hall sensor had issues. Sent components back to DA. Found wire fractures on the ignition side of the cable and a wire fracture on the hall sensor side as well. Put a new wire on the ignition side and sold me a new hall sensor. Haven't tried the new igition yet, as I still have my buddies ignition system off the DA85. Yes, they are identical, and yes, he is a lifelong friend. Has been and always will be.

[RustyTumbles]

My first DA50 had a bad hall sensor from the factory. I went to start it up in the back yard and 100 or so flips later I couldn't get it to start. I rang DA Australia and howie went though a few checks with me over the phone and we worked out the hall sensor had an open circuit. The next day I had the replacement part and the motor running.