PGR

My Feedback: (4)

I have a new 106 with about 2 gallons through it.
Problem: after approximately 4 to 5 min. into the flight the engine starts to mis-fire and cut out badly.The 1st 3 to 4 minutes the engine runs perfectly,then will barely keep running. I land the plane let it sit for 15 to 30 minutes fly again and the same thing happens .

Solutions tried but did not help:

1)changed ignition battery from a 1700ma 4.8v nicad to a 7.2v 1800ma power flight with a 5.1v regulator also tried a 6v regulator

2)Changed out the ignition module 3 times!!! no help.

3)Changed out the plugs.

Also... I bypassed the ignition switch( plugged the battery directly into the module)..no difference.

I flew the plane with the cowl off and still no difference.After 4 to 5 minutes the extreme mis-firing started again. No change in plane attitude will affect or change the mis-firing condition.

I checked the cylinder head temperatures during the mis-firing condition just after i landed rear cylinder 170 deg. front cyl.180 deg.

Like I said above the engine runs flawlessly for approximately 4 to 5 minutes then all hell breaks loose. Land let it sit fly again 4 to 5 min.

This is 3w's new Ignition with the tach.lead and the LED hook up.

The hall sensor was also replaced.
I have a new Da ignition I was thinking about trying.
Does any one Know how to do this? The 3w's hall sensor is a 4 wire sensor with 2 magnets.The Da's hall is a 3 wire with 1 magnet.

Thanks for anyone's help

Rick

mglavin

My Feedback: (31)

I'd be willing to bet something is growing with heat and possibly causing an air leak. Which in of itself seems back-wards as heat causes expansion. BUT me thinks it's likely... Have you tried to snug up all the bolt's on the engine.

Does this happen on the ground or only during flight?

The DA and 3W sensor's are not compatible. If it was an ignition related problem I'd think you'd have eliminated it after the third change-out. 3W's ignition problem has long been corrected and was primarily contributed to an inferior plug/cap insulation medium which broke down after some use. Of course there has been other problems but nothing that was a common occurrence. Most of the problems I see are poor and or inadequate wiring, soldering, switches and connectors.

bob_nj

My Feedback: (62)

Obviously you've contacted one or both of the distributors? What is their take on it? You probably already know this, but I was told the new style 3W ignitions with the extra sensor wires are not compatible with the older style engines. Keep us posted_bob

PlaneInsane

My Feedback: (5)

Had the same problem on a QS 106 and it turned out to be the sensor.

bob_nj

My Feedback: (62)

Which Sensor?

PlaneInsane

My Feedback: (5)

The sensor bolted to the front of the motor.

bob_nj

My Feedback: (62)

Did yours act the same way as the engine that PGR has? Mine seems to stutter on a high rpm upline, but not exactly sure what to make of it? Is there a way to test the sensor other than running the engine_bob

PlaneInsane

My Feedback: (5)

This engine would start off ok, but after things got warm it would get worse. By the end of a flight it was stuttering all the time.

The only way we found out it was the sensor was by taking one off of a 150QS that was known to be good. Problem was solved.

bob_nj

My Feedback: (62)

Did you bring that to the attention of the supplier, and is this a known bug? Kind of makes you wonder if it will just up and quit at the most in-opportune time

bhall01

My Feedback: (4)

Is it possible that the ignition module itself is getting too warm? Got the following off of the Cactus Aviation website where they were giving the spec.s on the new 3W ignition:

"Like all other electronic devices the ignition box gets warm under operating conditions. For that reason a simple airflow has to be guaranteed. Therefore, the four delivered rubbermounts have to be used for installation, insuring a 1mm gap underneath the box."

Just throwing out a possibility for consideration - several minutes into the flight is when you'd expect things to be warming up....... might be worth a check.

Hope you get it figured out - MY 3W 106 should be arriving on Wednesday, and I'd like to know what your resolution is, just in case I find myself in a similar situation!!

Good luck -

Barry

PlaneInsane

My Feedback: (5)

We also had changed out the ignition unit from the 150QS to the 106. These units were mounted upside down to prevent the component side from getting hot.

Gerhardt warrantied the sensor. And as far as I know it's not a known or common problem.

PGR

My Feedback: (4)

Spoke with bobby at cactus, he said to send him the motor and he would check the crankcase for a leak. He suspects a leak is developing in the crankcase after the engine gets warm.


I did replace the hall sensor, still same problem.

I'll let yall know the outcome as soon as I get it back.

Rick.

Falcon12514

My Feedback: (1)

My friend had the same problem with his DA 100, a whole bunch of dead sticks, after about 2 minutes into flight. He had air into his system, very hard to see, and his engine is brand new. Replaced the fuel tank, and all new tubing twice, and after a whole bunch of trouble shooting and found that his check valve on the carberator wasn't working properly, and cloged. Put in a new carbartor kit in it and problem is fixed!!!!