Erratic RPM on one mag

[cbennet12]

I'm still having erratic RPM readings but only from the left mag. I've increased the resistor on that line from 30k to 100k ohm. Zero improvement.

If I run only on the right mag, the RPM is stable. On either the left or both, RPM fluctuates RAPIDLY by 1500+ RPM.

Anything else I can try on the Skyview front or do I have a possible mag issue? They are approaching 500 hours but appear to operate normally.

Thanks,
Craig

 

[dabear]

I had a similar issue. Tried higher resistor, etc.

It was loose connection in the mag. Check your mag.

Bear

 

[dynonsupport]

Resistors are only something worth messing with if the issue was there on your very first flight. If it starts happening when you're hours into your flying, then something else is up.

As bear says, a loose wire is one possibility. The other is a mag that is wearing out.

 

[preid]

Resistors are only something worth messing with if the issue was there on your very first flight. If it starts happening when you're hours into your flying, then something else is up.

As bear says, a loose wire is one possibility. The other is a mag that is wearing out.

Same with EGT readings. There are three now that I tightened the connection, zero issue since.

 

[dynonsupport]

I'm still having erratic RPM readings but only from the left mag.  I've increased the resistor on that line from 30k to 100k ohm.  Zero improvement. 

If I run only on the right mag,  the RPM is stable.  On either the left or both, RPM fluctuates RAPIDLY by 1500+ RPM.

Anything else I can try on the Skyview front or do I have a possible mag issue?  They are approaching 500 hours but appear to operate normally.

Thanks,
Craig

We've had customers that have had to increase the resistor values to as much as 150K, so don't give up on increasing the resistor value quite yet.

 

[cbennet12]

Re: Erratic RPM on one mag-Solved

I hate to admit it was the obvious but wanted to share for the good of the next person...

Loose p-lead connection at the mag. Tightened it up and RPM is rock solid.

Thanks to all for the feedback.

Craig