At 09:07 AM 3/19/99 -0600, Perry Robinson wrote:
>.... I have a 1961 MGA 1600 .... the engine has maybe 6,000 miles on it
since a full rebuild. .... never had a problem.
>
>.... When I go to start it, it turns over very slowly, .... as though the
starter is straining to turn it. Sometimes the jumper cables get very hot,
or the circuit breaker trips on my 200 amp booster. I have repalced the
starter twice, with a "guaranteed" starter, but no luck.
>
>.... you can push it to a good roll, pop the clutch in second, and it will
buck once, this start like a champ!? I've been told that I may have a piec
of crap starter, that the ground strap may not be good (checked that), or
that my static timing may be too far advanced. ANY IDEAS?
>....
The timing could be too far advanced, such that it fires before TDC and
causes a kick back that stops the starter from getting it over the top.
However, If it started okay before it was parked, it's not likely that the
timing could have changed that much by itself, so probably not.
200 amps is about the right current if the engine was very stiff and the
starter was working very hard to turn it. However, as you can easily push
start it, the engine is turning freely, so not that much load for the
starter. An engine of this size should crank over with about 100 amps.
What that leaves is a starter motor that is connected well enough
electrically to draw 200 amps but doesn't put out much torque. Sounds like
a bad starter to me. Put a voltmeter directly on the input terminal of the
starter motor, with the second meter lead grounded on the housing of the
starter motor. If it reads at least 8 volts when it's cranking slowly, it
probably has some internal short. If it reads closer to 12 volts when
cranking slowly, then probably some internal open circuit(s) in the
armature, or maybe a bad connection for the brushes on the armature.
Barney Gaylord
1958 MGA with an attitude
|