Erratic RPM Display

[snowyriver]

I have a murphy rebel with an 0360 in it. My rpm display jumps all around with the eng at a steady rpm. I have gone all the way to 150K resistors and they have helped but not completely. I do notice that when I go to one mag in flight the rpm is steady. Dynon support says I might try stronger resistors. Anyone have similar issues with a similar engine?

I have the dynon leads crimped with the respective wire from each mag and then attached to the ignition switch terminal. Thanks, Craig

 

[dynonsupport]

Is one mag OK and the other erratic, or is it fine one just one mag no matter which one you run?

If it's always one mag that is erratic, that can be a good sign that mag is failing. Resistors won't help if the issue is that it's only erratic when you are on both mags- that's a new one. Are you sure you have the mags wired to the RPM inputs correctly? If you wired them both to the left or right input, you'd get that behavior.

You can see the RPM for each individual RPM input channel in the EMS debug page. This will help tell you if it's one input that is crazy or both. Note that SkyView always shows you the highest of the two RPM inputs.

 

[cbennet12]

I seem to be experiencing the same issue. It started about 4 months after installation so my assumption was that my resistor installation was not robust so I replaced them with a new setup - no change.

I have not tried checking to see if it's tied to one mag.

Have you had any luck fixing this?

Craig

I have a murphy rebel with an 0360 in it.  My rpm display jumps all around with the eng at a steady rpm.  I have gone all the way to 150K resistors and they have helped but not completely.  I do notice that when I go to one mag in flight the rpm is steady.  Dynon support says I might try stronger resistors.  Anyone have similar issues with a similar engine?

I have the dynon leads crimped with the respective wire from each mag and then attached to the ignition switch terminal.  Thanks,  Craig

 

[jakej]

David B

You should give your input here due to your issue with this same problem

Jake J