Lightspeed Ignition Misfire

[LifeofReiley]

Originally Posted by AlexPeterson

A trick that might help keep this type of plug boot on is to push them on until one can feel the metal portion inside engage the plug. Then, while rotating slightly back and forth, advance the boot (the end towards the plug) a little more. Without doing this, it is easy to build some compression in the boot, which tries to push the connector away from the plug. Preferable is to have some tension in the boot, holding the connector onto the plug.

Thanks Alex, we'll add that to our bag of tricks.

Darrell

[chaskuss]

Originally Posted by LifeofReiley

Anybody using safety wire or some other method to secure EI spark plug leads on the sprark plugs? I also had #3 lead come off Saturday... well it was detected on run-up during the mag off check. No earlier symptoms or signs of a problem was noted in the previous flight. Okay, back to the hangar, pull the cowl and plenum top just to find a #3 wire no longer snapped securely on the spark plug. Any Suggestions?

Reiley,
Obviously, the folks giving you advice are not auto mechanics. Installing automotive style wires on spark plugs takes a bit of finesse. The reason the wire came off the plug is because of pressurized air. Automotive spark plug boots fit so tightly, that air gets trapped inside and is under pressure. This pressurized air can cause the boot to vibrate off. The proper technique is to use an O-ring pick (miniature ice pick) and a can of silicone spray.
First, apply silicone spray to the wire behind the boot and inside the boot. This will allow the boot to slide freely along the wire (once you get it moving). Next, carefully insert the O-ring pick between the insulation of the wire and the boot. Spray more silicone spray (Gary's It is one brand) into the gap between the pick and the wire. Dish soap and water will substitute for Silicone Spray in a pinch. Make sure you get the sharp end of the wire all the way past the area where the boot firmly contacts the insulation of the plug wire. Slide the boot back an inch or two on the wire, leaving the pick in place. Install the wire on the spark plug (or the coil end for that matter) till you hear the metal terminal "click" in place. Now advance the boot with the O-ring pick, over the spark plug. The pick creates a space to allow the air to escape. You are now ready for the next plug.
An alternate method is to install the wire on the plug and then insert the O-ring pick till you hear the pressurized air hiss out. Using this method, make sure that the terminal is "clicked" onto the plug. It is also good practice to apply a dab of Permatex dielectric tune up grease between the terminal on the spark plug and the terminal on the wire. Same holds true at the ignition coil end. The grease is available at all auto parts stores.
The wire will not come off when done this way. If the boot tried to back out, a vacuum would be formed, preventing it from coming off.
Charlie Kuss
PS The purpose of the grease is to prevent corrosion between the terminals

[LifeofReiley]

Originally Posted by chaskuss

Reiley,
Obviously, the folks giving you advice are not auto mechanics. Installing automotive style wires on spark plugs takes a bit of finesse. The reason the wire came off the plug is because of pressurized air. Automotive spark plug boots fit so tightly, that air gets trapped inside and is under pressure. This pressurized air can cause the boot to vibrate off. The proper technique is to use an O-ring pick (miniature ice pick) and a can of silicone spray.
First, apply silicone spray to the wire behind the boot and inside the boot. This will allow the boot to slide freely along the wire (once you get it moving). Next, carefully insert the O-ring pick between the insulation of the wire and the boot. Spray more silicone spray (Gary's It is one brand) into the gap between the pick and the wire. Dish soap and water will substitute for Silicone Spray in a pinch. Make sure you get the sharp end of the wire all the way past the area where the boot firmly contacts the insulation of the plug wire. Slide the boot back an inch or two on the wire, leaving the pick in place. Install the wire on the spark plug (or the coil end for that matter) till you hear the metal terminal "click" in place. Now advance the boot with the O-ring pick, over the spark plug. The pick creates a space to allow the air to escape. You are now ready for the next plug.
An alternate method is to install the wire on the plug and then insert the O-ring pick till you hear the pressurized air hiss out. Using this method, make sure that the terminal is "clicked" onto the plug. It is also good practice to apply a dab of Permatex dielectric tune up grease between the terminal on the spark plug and the terminal on the wire. Same holds true at the ignition coil end. The grease is available at all auto parts stores.
The wire will not come off when done this way. If the boot tried to back out, a vacuum would be formed, preventing it from coming off.
Charlie Kuss
PS The purpose of the grease is to prevent corrosion between the terminals

Sweet... I put his in the file too.

Thanks!

[smetzger]

I know it's kind of late to post to this thread.

I have a Slick mag on the upper plugs and a Lightspeed on the lower plugs of my Glasair III. A few weeks ago I was flying and thought I noticed some roughness, so checked both ignitions and, sure enough, the Lightspeed was missing on number 2 (EGT on each cylinder makes this super-easy to diagnose). Pulled the cowls and sure enough the #2 lead had come off the plug. Pinched the contact ring a touch and buttoned it up, and lo and behold it was still missing on #2.

Turns out that the coils used by Lightspeed are especially sensitive to being run without being connected to a plug. Maybe 45 minutes of run time had roached the coil with the high tension lead voltage unconstrained.

Moral of the story is to suspect the coil if you realize you've run for any period of time without a plug connected. Buy an extra because you'll need it. I still love the Lightspeed, though. Easy starts and smooth running when it's all connected properly.

-Steve Metzger
RV8AQB - Fuselage in progress

[Bob Martin]

Originally Posted by smetzger

I know it's kind of late to post to this thread.

I have a Slick mag on the upper plugs and a Lightspeed on the lower plugs of my Glasair III. A few weeks ago I was flying and thought I noticed some roughness, so checked both ignitions and, sure enough, the Lightspeed was missing on number 2 (EGT on each cylinder makes this super-easy to diagnose). Pulled the cowls and sure enough the #2 lead had come off the plug. Pinched the contact ring a touch and buttoned it up, and lo and behold it was still missing on #2.

Turns out that the coils used by Lightspeed are especially sensitive to being run without being connected to a plug. Maybe 45 minutes of run time had roached the coil with the high tension lead voltage unconstrained.

Moral of the story is to suspect the coil if you realize you've run for any period of time without a plug connected. Buy an extra because you'll need it. I still love the Lightspeed, though. Easy starts and smooth running when it's all connected properly.

-Steve Metzger
RV8AQB - Fuselage in progress

This exact same thing happened to a RV-6 buddy of mine too.
His was the #1 bottom plug wire.
He now keeps a spare coil.
Klaus recommends a single EI system be installed on the TOP plugs and
I'm pretty sure it has to do with flame front performance, but it sure helps
with plug wires not falling off as well.

[wv4i]

Not just with EI coils, but an open or high resistance plug or wire will also take out a Slick magneto. Will burn the the rotor and associated stator. Ask me how I know. Slick 4370 = $635 fm Spruce.....it's only money and time.