Stumped by new starter

I'm stumped by a problem with a new (rebuilt) Prestolite starter. Bare with
me while I go through the details.

The left engine starter had been causing us problems, the bendix wouldn't
engage every time. We also had a problem with the right bendix but only on
occasion, so we thought we just needed them torn down, cleaned, lubed, and
re-installed. Right starter bendix was cleaned lubed, no problems. Not so
lucky with the left. The shaft was twisted almost 1/4 turn. Currently
bendix parts are back ordered for everybody, so junk it, and install a
rebuilt.

So we installed a rebuilt Prestolite. After we installed it, we cranked the
engine several times and the starter sounded and acted great. This weekend
we flew the Aztec for the first time with the new starter and it acted fine
until we shut down and attempted to re-engage the bendix. This is part of
our normal shut down procedure in cold weather, just to insure that when we
get back in the plane the bendix is already engaged and won't hang up due to
the bendix lube thickening in the cold weather. This time it just sat there
and spun, it wouldn't engage. We tried about 10 times with no luck.

Finally after going into the FBO for awhile, we returned to the airplane and
this time started the right engine first, then attempted to start the left.
Our thinking was that maybe the left engine starter bendix wasn't getting
enough voltage to engage. On the first attempt with the right engine
running, the left bendix spun. The second and third attempt the bendix
engaged and the starter cranked the engine as normal. After we landed back
at home, we left the right engine running, shut down the left, then engaged
the left bendix with the right engine running. It engaged perfectly.

So what's going on? Anybody ever have a limited voltage problem cause a
bendix not to engage? Is this theory plausible? probable?

The battery should have had plenty of juice, this all happened immediately
after a 45 minute flight and both alternators were charging and the battery
showed a normal charge, no discharge.

My next thought would be the starter cable. They are not original cables,
but they are aluminum, not low-loss copper.

Next thing to do I suppose is to pull the cowl and check the
voltage/amps/ohms at the end of the starter cable.

Wondering if anybody has had this problem.

Thanks.

Jim

"Jim Burns" wrote in message
...

The battery should have had plenty of juice, this all happened immediately
after a 45 minute flight and both alternators were charging and the
battery
showed a normal charge, no discharge.

Remove the battery and replace with another one, fully charged. If you can
dup the problem, _then_ you know it's not the battery.

It is possible that misalignment between the starter and flywheel is
torquing the Bendix shaft (which caused the problem with your old starter).
Otherwise, you may have gotten a defective rebuilt starter. Happens all the
time, and should be covered under warranty.

The Bendix should engage the starter even when there is insufficient voltage
to crank the engine. The battery and/or cables are not likely to be the
source of your problem

--
-Elliott Drucker

On 10-Jan-2005, "Jim Burns" wrote:

Bare with me while I go through the details.


Why? Do we have to be naked to understand the problem? ;-)
--
-Elliott Drucker

Jim Burns wrote:
snippage
: I'm stumped by a problem with a new (rebuilt) Prestolite starter. Bare with
: me while I go through the details.

: So we installed a rebuilt Prestolite. After we installed it, we cranked the
: engine several times and the starter sounded and acted great. This weekend

: So what's going on? Anybody ever have a limited voltage problem cause a
: bendix not to engage? Is this theory plausible? probable?

I had a similar problem this summer. You can probably google it. I had a worn
out bendix, and I ordered a new one (the last one in the US!) from Sacremento
Sky Ranch. The new one was no good, too, and exhibited the exact symptoms
that you have. I was able to make one usable bendix from the new one and
the worn-out one.

(The worn-out one had the bearing at the end of the flywheel drive gear cup
totally worn out and falling apart, and would hang up and not retract after
the engine started. The new one had the helical gear and pawls mis-
assembled, but the drive cup was A-OK, so putting the new drive cup on
the old helical gear assembly made everything work great.)
--
Aaron C. (N9376J)

writes:


The Bendix should engage the starter even when there is insufficient voltage
to crank the engine. The battery and/or cables are not likely to be the
source of your problem

But...by starting the other engine first, there's a lot of vibration
that does not exist in the other case. And vibration unsticks
things...


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

New reality program on cable... "The Naked A&P"

wrote in message
news:43JEd.1309$SS6.1099@trnddc07...

On 10-Jan-2005, "Jim Burns" wrote:

Bare with me while I go through the details.


Why? Do we have to be naked to understand the problem? ;-)
--
-Elliott Drucker

1) Check the battery, it may be bad even though it doesn't seem bad....
I'll buy that, I've got a jumper/starter/battery charger that I can run
directly to the starter leads.

2) The rebuilt starter has a bad bendix. Bendix has been recalling parts
lately, it could have some bad ones in it.

3) One fellow on another forum had a bad battery cable causing the problem

4) Another fellow on another forum didn't have the correct washers and nuts
on the starter stud, causeing arching.

5) Misalligned starter gear w/ring gear causeing binding and old starter
shaft problems as well as new starter shaft problems.... OK. the starter
mount has 2 alignment studs and 4 bolts, everything lined up good there and
it tightend up flush to the engine. So does that mean that the ring gear
might be misalligned? That's starting to sound spooky.

I stopped by our hanger tonight to have the latest Janitrol heater AD
complied with and thought I'd tempt fait. I bumped the starter on the left
engine about 5-6 times and it engaged every time. So I guess we'll just
wait and see what happens next.
Jim

On 11-Jan-2005, "Jim Burns" wrote:

I bumped the starter on the left engine about 5-6 times and it engaged
every time.
So I guess we'll just wait and see what happens next.


If you didn't actually start the engine, then the starter most likely
remained engaged between "attempts". It is the ring gear "driving" the
starter gear after the engine starts that causes the Bendix drive to
retract.

--
-Elliott Drucker