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pMags on the IO-390

Carl,

I'm thinking of doing at least one but maybe both. When doing both, does the left one have the impulse coupler, and do you need to buy a replacement gear?
 
n982sx said:
Carl,

I'm thinking of doing at least one but maybe both. When doing both, does the left one have the impulse coupler, and do you need to buy a replacement gear?
Click to expand...

You do use the gear off the right mag. You cannot use the gear that is on the left mag (the one with the impulse coupler). eMag will sell (and install if you like) a gear for you for the left side. eMag buys standard Lycoming mag gears in bulk and sells them to customers at a discount.

Remove the left mag and then remove the mag impulse coupler spacer. As you no longer have the mag impulse coupler spacer on the left side, you may wish to replace the mag engine studs with shorter ones to match what is on the right side.

Carl
 
rvbuilder2002 said:
The one in the prototype does and it starts just fine with just the left mag being an Impulse.
Click to expand...

Hmm...I guess I am having a silly brain moment. I thought mine had a left mag that was set up for a Slick Start. I will have to open the box and look again. I guess that is what I get for thinking sometimes...:D
 
NGK plug

The correct plug for this application is the Denso IKH27. Amazon has them: [url said:
http://www.amazon.com/Denso-Iridium-Spark-Plug-IKH27/dp/B000M6URAA[/url]

Carl
Click to expand...

I used the Denso for a few years on my IO 390 but found this alternative: NGK LZFR5C-11 Spark Plug #NGK-92174

I don't know that fine wire is really necessary with an electronic ignition. The NGK's are much less expensive and work just as well.

Don
 
What is the standard timing on the IO-390 engine?

I ask because you want to make sure the P-mags are configured correctly, which can be done with either the EICAD program available on the Emag website or with our EICommander.

The P-mag w/o the jumper in is set to a little over 30 degrees, which is great if you are flying behind a Continental A65 but not so good for a Lycoming O-320 or larger.

With the jumper in, they fire at 26 degrees before TDC, which works for most standard parallel engines. However, if you have high compression pistons, you might want to think about moving it down a few degrees and if you have an angle valve engine, it should be set to 20 degrees.

If you are buying new P-mags, they will have firmware version 40 (or higher) and should be set to TDC when timing them. There is no need to clock them as some have done with light props and earlier firmware versions.

PS. I will be demonstrating the P-mags and the EICommander at OSH again this summer. Watch the forums for the date, time, and location.
 
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