RV-12 Rotax 912 ignition mod

[John Acardo]

Engine has 650 hours, when cycling the A ignition mod, more than 500 RPM drop and rough. All wires tight. Thoughts on is it ignition module or coil?

How to test?

Thanks

 

[JBPILOT]

GREEN STRIPE IGN MODULES ?

How old is the engine. If green stripe, then you likely have a bad ign module.

 

[rvbuilder2002]

Engine has 650 hours, when cycling the A ignition mod, more than 500 RPM drop and rough. All wires tight. Thoughts on is it ignition module or coil?

How to test?

You have two, so the common troubleshooting procedure is to begin swapping connections between them and see if the problem moves to ign. B.

 

[DHeal]

Have you checked that the ignition trigger coil gaps are per spec? See Section 4 of:
https://www.rotax-owner.com/manuals/MMH_912-914_Series_ED1_R6.pdf

Also see Step 2 of:
https://www.vansaircraft.com/wp-content/uploads/2019/04/46_12.pdf

 

[printbr]

I had the same thing happen recently. It turned out to be a broken insulator around the electrode on a spark plug. If it runs rough when lane A is turned off then check the #1 & 3 bottom plugs and then the #2 & 4 top plugs. Or since they are cheap replace all the plugs and see what happens. Don't forget to use enough heat paste on the threads so you don't break another plug.