Those starter teeth are part of the problem. Getting a new pinion gear for
it through a rebuild/new starter will help relieve this.
Second possibility could be the ring gear on the flywheel. Pinion gears are
usually made of a less durable metal, so they would wear out first, but don't
rule out the flywheel. Some scalloping of the pinion gear is designed
in to lessen the harshness of metal on metal contact. (But I believe you know
all this)
Cars, like people, have habits. One engine habit is that a motor will
usually spin to a stop at the same crank/flywheel position when you shut
down. Hitting the ring gear in the same spot for 26 years with a starter is
apt to create some wear. Based on your description
I think that the starter is coming around to this a point on the flywheel
with less than great teeth, trying to mesh with the worn starter teeth and
saying, Wheeeee!. You might not have broken teeth on the ring gear, but
unless you've ever replaced the ring gear, its probably pretty worn and
can contribute to the condition The teeth aren't worn on the other side
simply because they never contact anything (you are right on the load issue.)
Engines and Starter motors only spin one way each (or supposed to, anyway)
My 80 spit does something similar even with new starters/pinion gears. Its
better with the new starter, but every now and then, it whines. (Design
defect?) I have to let it stop whining before I give it another go. One
temporary kludge fix when it doesn't hit initially is to rock the car forward
OR back while in gear to spin the engine/flywheen 1/4 or 1/8 turn to show new
teeth to the starter. I've also replaced the starter solenoid (there's a
ford replacement part I got in Walmart that's almost an exact match, looks
much sturdier than the lucas part), that also may be part of the solution.
Third possibility: If you're able to crank and crank and crank and crank and
crank, and then it starts the giving out/free-wheeling cycling, maybe the
starter motor is overheating. (Sounds like the most reasonable answer, given
what I perceive you to know/tested and your description of events)
Also, anything to speed up the startup would make this less of a problem. Is
your startup cycle when cold overly long to begin with (choke problems?)
Would you put in an electric fuel pump so you don't have too crank to fill
the bowls or are you a purist? I'm assuming your car is in a good state of
tune....
(Sounds like your girlfriend got the better part of the deal, buy a car
and get a free mechanic....Maybe that's something the the lemon law should
incorporate)
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REPLY FROM: Scott R. Cypher
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Although I sold the 69 Spitfire to my girlfriend, I still work on it. The
latest problem is starting.
The starter will engage initially quite well, and crank the engine
around. At some point the starter disengages, and makes that rrrrrooo sound.
The engine isn't even close to starting yet. It takes her about 10-15
cycles of this rr-rr-rr-rrrrroooo to get going. Even when I do it, it
takes me about 5 trys.
When the engine is warm it starts right up so we don't get to the
premature disengagement.
OK... I pulled the starter and examined its teeth. They are quite shiny
with severe scalloping toward the starter motor side. Would this cause
the disengagement, or is it a symptom of something else? The starter in
my parts box has wear in the same pattern, though slightly less severe.
The teeth are >not< shiny toward the opposite side from the motor.
Doesn't look like they are taking a load there at all.
Remember, the starter always engages the first time (so I don't think it
is a broken tooth on the ring gear) and cranks for many revs the first
time (filling up the carb bowls after a long sit). It never makes the
scraping noise I associate with broken teeth. It just gives up a touch
too soon.
I'd like to put a new starter in, but don't want to wear it the same way
as the last two if it's abnormal.
Thanks!
John M. Trindle | jtrindle@tsquare.com | Tidewater Sports Car Club
'73 MGB E Stock | '69 Spitfire E Stock | '88 RX-7 C Stock
Home Page: http://www.widomaker.com/~trindle
"Ginsberg's Restatement of the Three Laws of Thermodynamics:
You can't win.
You can't break even.
You can't quit."
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