PMag Tming Question

PMag Timing Question

So, I am about to do the first engine start and will be re-timing my PMags to retard timing by a few degrees to ensure that I don't get a kickback at start since I'm using a Catto prop, per the manual. I currently have the jumper installed to enable the factory A curve, but am planning to remove it to restore some of the advance after I finish this re-timing.

My thinking is that by going to the B curve, after retarding the timing by 3-4 degrees, I am essentially restoring A curve advance at higher RPMs. For those PMag gurus out there, does this make sense? Unfortunately, you can't rely on the advance diagram published in the manual, so I feel like I'm groping a little in the dark. Thoughts?

I think if u have the latest firmware, the anti-kickback is already built-in.

revenson said:

I think if u have the latest firmware, the anti-kickback is already built-in.

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I don't have that yet. That's why I'm doing this. At some point, I'll pull them and send them in for upgrade. In the meantime, this is my strategy.

You will need to retard it very little to stay on the safe side and I would stick to the A curve till you have some time on the engine and have more data on your temps and cooling. It is very easy to go push it farther to the B curve

Pull them and send them in before the first engine start.

I can't stress this enough!

Version 40 of the firmware fires the plugs at 4 degrees AFTER TDC for starting, which eliminates the kickback problem.

That version also has a software fix that eliminates lost timing issues.

Again, get them in for the update before your first engine start!

As for the timing, if you have a standard 8.5:1 compression parallel valve engine, you want the jumper in to force them to the "A" Configuration.

More info on PMag?

Is there a web site for PMag and/or a thread here on VAF? I'm looking for more info.

Thanks,

Jim

Jimd said:

Is there a web site for PMag

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Search for EMag (the company) and PMag (the product) and you should find their site.

Thanks

Ray, thanks! I'm a bit out of the loop on ignition systems. I had LASAR installed when Mattituck built my engine almost 10 years ago. Now with the apparent lack of parts and high costs and lack of shops willing to inspect and overhaul them I'm trying to find another solution.

If anyone has had a LASAR system inspected and overhauled please let me know, that may still be an option for me, but the shops that we would typically use do not want to look at them.

Thanks,

Jim

Jim,

Here is a thread you might be interested in reading. Another member replaced his Laser system too, but not with PMags. There are many threads on comparing them but, for 6 cylinder folks, the options are far more limited at this time.

http://www.vansairforce.com/community/showthread.php?t=140667

Ray,

Thanks. I'm not sure it matters at this point, my installation in on a TMX 0-360 four cyl with high compression cylinders.

I'm trying to come up to speed on the options.

Jim