Starter question

On Jan 30, 9:21 pm, (John_F) wrote:
Do NOT use WD40!! WD40 turns into a stickey mess in a short period of
time. After using WD40 in a few months or less the bendix will stick
and will not extend to engage even though the starter spins. Use 50%
motor oil and 50% STP or straight 50w motor oil NOT WD40.

On Tue, 30 Jan 2007 23:42:17 GMT, A Lieberma
wrote:



A Lieberma wrote in
.18:

Update to the below posting.

My A&P pulled my plane in. Bear with me on this, but the bendex or
selenoids????? needed a good WD40ing and that fixed the starter problem.
MY GUESS is the cold weather gummed up the works? Dunno.

The starter is still in good shape from what my A&P said. It's an
prestolite starter for those that asked what kind of starter I had in my
plane.

I described the problem in the third paragraph in my original post,
initially, when he called me, he said I had a bad turn coordinator
causing the noise that I best described to him as a gyro winding down
after the master switch was put on.

He called me back a second time and said, it wasn't the turn coordinator
that was broken. The turn coordinator wasn't getting enough volts to
keep it running, so it would start up, and then shut down as the battery
was only putting out 9 volts.

I had a new battery installed in 02/03, so I guess I was on the end life
of the battery.

This should fix all problems (I hope) and will fly it in the pattern
tomorrow to make sure all systems are go.

Now, all of this raises a couple of question. Exactly what is the
ammeter for if I wasn't showing any sign of discharge on a battery not
running full tilt?

When I put the master on, it was exactly where it is everytime I started
the plane, with no sign if discharge. I know the meter works, as when I
put my landing light on, it will swing to the left. When I fire the
engine, the needle swings slightly right and settles back in the middle.

When the battery does go belly up, does the starter click like a car when
a bad battery is the problem?

Thanks all for the input!

Allen

Went flying today. Go to crank the engine for start, nothing. Turn
the key, got like a jiggle of the prop. Turn all electrical things
off, figuring the battery drained, and then started just the alt and
bat, same thing, jiggle of the prop. Tried once more, and got the
prop to turn and fired right up.

Just had the durn starter replaced in July with a new one.

I don't think it was the battery, as nothing moved when I turned the
key, just a strange noise, no clicking like it would sound with a dead
battery. When I fired up the master and alternator, I heard a noise
sounding like something was draining the battery, yet the meter was
stable in the middle, not indicating any discharge.

Last week, when I cranked it, it struggled on the first turn of the
prop, but it started, so I had attributed it to maybe my battery being
low, it being very cold by MS standards, but after today, watching the
electrical amnmeter, the load was fine once the engine was running.

Am I having a bad run of starters, or should I be looking elsewhere
for a problem?

Grant you, I try to fly two times a week, but I would think I would
have gotten more starts out of this starter then 6 months worth.

Plane normally starts with one or two turns of the prop, so it's not
like the starter is running for any period of time or been abused.

Allen- Hide quoted text -

- Show quoted text -

I thought STP turned pretty sticky after a while. It is Silicone spray
that you are supposed to use on starter bendixes I thought. The STP
and motor oil mixture is an old formula used to make a good engine
assembly lube, since it does not run off the internal metal parts
during long term storage.

Bud

On Jan 30, 10:21 pm, (John_F) wrote:
Do NOT use WD40!! WD40 turns into a stickey mess in a short period of
time. After using WD40 in a few months or less the bendix will stick
and will not extend to engage even though the starter spins. Use 50%
motor oil and 50% STP or straight 50w motor oil NOT WD40.

Lycoming says to use only silicone spray lube on the starter
drive. It will not attract dust as all other lubes will, and dust plus
oil equals sticky sludge. You might need to remove the starter, take
the drive out and clean it thoroughly.
Many starting problems involve old contactors, both the master
contactor and starter contactor, and both are usually found on the
firewall or battery box. These things aren't airtight, and oxygen gets
into them and causes oxidation of the copper contact disc and teminal
heads. That oxide is not a good conductor and will result in some
resistance, which causes more heat, which accelerates the oxidation.
We have to regularly replace contactors on our six flight school
airplanes, and when we buy another (used) airplane we usually replace
both of them right off simply because of their age. A low-time
contactor will still be oxidized because of the years since
manufacture. A bad contactor can ground an airplane far from home and
cause us expensive repairs. A new battery is just a waste of money,
trying to fix the wrong problem.
Another problem: old ignition switches. The contacts in these are
lubricated with a grease that hardens with time and lifts the contacts
apart. Arcing occurs and the switch soon burns out. There are ADs
against some of these switches.
There is no contactor inside the Prestolite starter on a Lyc.
There IS a 200-hour brush inspection requirement, because worn brushes
or commutator will cause starting problems. And a lousy contactor or
tired battery will result in much longer crank cycles, which heats the
starter and melts the solder joining the armature wires to the
commutator segments, or will melt the segment bonds and they'll be
thrown out. End of $450 starter. See how an old $25 contactor can
cause many more problems?

The OP mentioned turning off the radios and other stuff to try
to start. Radios should be turned off before turing off the master at
the end of a flight and left off until the engine has been started
again. Some radios have no voltage spike protection. Some aircraft
have a diode across the master contactor coil to shunt the spike, some
don't, and some of those diodes are busted. Some starter contactors
have diodes, many don't. The starter has no diode. Some aircraft have
a relay that opens the supply to the avionics during the start, many
don't.
Any contactor has a coil, the starter has several coils, and
the alternator has a field coil. All coils create a sharp voltage
spike when the current is cut off. Switching the master off, the
alternator off, or releasing the start switch all create that spike
(I've measured the master contactor's spike at 600 volts) and those
expensive radios aren't all built to put up with it, especially
considering that the spike creates an electron flow in the wrong
direction through the bus. That's why many aircraft have an avionics
master switch (that has no coil involved). The rest should have the
radios shut off before shutdown.

Dan

In article .com,
wrote:

Any contactor has a coil, the starter has several coils, and
the alternator has a field coil. All coils create a sharp voltage
spike when the current is cut off. Switching the master off, the
alternator off, or releasing the start switch all create that spike
(I've measured the master contactor's spike at 600 volts) and those
expensive radios aren't all built to put up with it, especially
considering that the spike creates an electron flow in the wrong
direction through the bus. That's why many aircraft have an avionics
master switch (that has no coil involved). The rest should have the
radios shut off before shutdown.

Coils (inductors) are current storage devices.
Capacitors are voltage storage devices.

On Jan 31, 6:53 pm, john smith wrote:
In article .com,

wrote:
Any contactor has a coil, the starter has several coils, and
the alternator has a field coil. All coils create a sharp voltage
spike when the current is cut off. Switching the master off, the
alternator off, or releasing the start switch all create that spike
(I've measured the master contactor's spike at 600 volts) and those
expensive radios aren't all built to put up with it, especially
considering that the spike creates an electron flow in the wrong
direction through the bus. That's why many aircraft have an avionics
master switch (that has no coil involved). The rest should have the
radios shut off before shutdown.

Coils (inductors) are current storage devices.
Capacitors are voltage storage devices.

As if current and voltage were independent of each other?
The coil will produce a surge of current, which has a specific
pressure that we call voltage. You can't have current flow without
voltage; any flow (amperage) requires pressure (voltage) to drive it.
Just like water in a hose.
The magneto produces a pressure upward of 20,000 volts. It
does this using a pair of coils and a switch (points). Your
automobile's ignition system probably produces 40,000 volts, again
using paired coils. Both of those systems have a primary coil that
produces the current surge (which has a voltage spike) when its
current flow is interrupted, and the collapsing magnetic field
produces the huge spike in the secondary coil for use at the spark
plug.
The argument re current vs. voltage is a little like
Bernoulli's vs. Newton's theories of lift. They're both right, but
they address different aspects of the phenomenon.

Dan

wrote in news:1170260453.042276.228590
@v33g2000cwv.googlegroups.com:

The OP mentioned turning off the radios and other stuff to try
to start. Radios should be turned off before turing off the master at
the end of a flight and left off until the engine has been started
again. Some radios have no voltage spike protection.

Hey Dan,

You did have me awondering.....

I turned all electrical stuff off is what I said (not radios). That was
nav lights, and strobes.

My check list has me turning on avionics after engine start and before
engine shutdown.

Allen