eng start - mag? lightpeed? both?

Which ignition system are people w/ one mag and one lightspeed starting on?

Start on mag

I have one slick mag and lightspeed on the top plugs, I always start on the mag. I was told you can trash your starter if you get a kickback starting on the EI.

I flew my Long EZ for 18 yrs with left mag and right top plugs wired to lightspeed EI. Electric starter.... cranked with mag & EI on during start and never had starter or starting problem that way.

Mike Rhodes
RV-9A T/U canopy in progress
9-1330

I start on both. My wiring diagram from 'lectric Bob says to use an EI with a non-impulse coupled mag. But, my mag does have an impulse coupler and is mounted on the left with the LSI on the right with Hall effect. Before my first engine start I called PennYan Aero who built and ran it in their test cell. They said that there is not a problem starting up with both. If they explained why - I don't remember. Sure would like to know, though. I guess the reason lies in the Lightspeed somehow and the fact that it is attached to the right mag hole.

You should start on the magneto only, EI should be off. This reduces the chance of a kickback during start. If you have a kickback and you are using one of the lightweight (CHEAP) starters, you will trash the permanent magnets in them.

Andrew,
Here is something from the Light Speed Engineering site:

"The current versions of Plasma CDI systems need a minimum of 6.2 volts to start operation. This is more than 2 volts less than the minimum voltage needed by the starter solenoid, thereby eliminating the possibility of kick-backs during starter operation.

Plasma systems shipped before December 20 of 2004, need 8.5 volts to start operation. This higher "on" voltage can cause a misfire if the starter current drain is high and/or the battery is weak and the voltage collapses below this threshold during cranking. Systems shipped before 2005, can be upgraded to have the lower voltage capability.

Once the engine is running, all systems operate down to less than 5 volts, should you lose your charging system."

Or use P-Mags who liaised with Sky-Tec to get around the kickback issue

Impulse mag and LSE and I start on both.

f1rocket said:

You should start on the magneto only, EI should be off. This reduces the chance of a kickback during start. If you have a kickback and you are using one of the lightweight (CHEAP) starters, you will trash the permanent magnets in them.

Click to expand...

This is no longer true if you have a current Lightspeed ignition. The voltage drop tolerance is now lower. Use a generous sized starter wire (2 AWG. I still use 4 AWG but plan up upgrade) and you'll never have a problem. I always start with E Ign (+1 mag) ON. After all thats one of the great advantages of EI. Easier starts. I use Skytec starter. If you use B&C you'll be even better off and never have to worry about this.

Steve
RV7A

Kelly E-Drive Starter

The new Kelly Aerospace E-Drive starter is specifically designed to be immune to prop kickback damage (via a clutch system). If you haven't purchased a starter yet, you might consider the E-Drive. Then you won't have to worry about which starting mode you choose. The E-Drive is virtually the same weight and cost as the wire-wound Skytec starter which needs a replaceable shear pin and starter disassembly to recover from prop kickback. Do a search on "E-Drive" and you'll find more info that I posted. Note: I'm not affiliated with Kelly Aerospace - - I just think they have "the latest and greatest" starter.

Good Luck!

Bill Palmer
Chino Hills, CA

Be very very careful

Sounds like the newer LS systems might be safe to use on starts; however, if your not sure about this technology, only start on the mag. I just recently dislodged my Cheap Starter due to kick back. I made a hot start with only one battery online (I usually start with two online). I am not sure if the kick back was due to slow starter speed or premature sparkilation. Anyway the older Electro Air systems require at least 8 volts to keep advance out of the equation.

Running EI with a starter motor can be risky business. I have gotten away with it many times before but not this time. Skytech Fly Weights are designed to break at a weak spot in their foundation and avoid damaging your ring gear. $150.00 plus shipping and your back in business with a new starter.