[Mgs] 1980 MGB Starter Problems

[Richard Ewald]

A high starter draw is caused by either low circuit resistance or high
mechanical resistance.
500 amps is an almost unbelievably high draw however.  A big block V8 with a
bad starter will draw a little over 300 amps and barely turns over.  500
Amps on a 4 cylinder makes me think that perhaps the ammeter is out of
adjustment.  Are you checking the spike, or what it takes to keep the engine
turning once it starts?  Disregard the spike, look at what it takes to keep
the engine turning once it starts to turn over.

Since you have tried one or two other starters with the same draw, it points
to high mechanical resistance.  The pulling of the coil wire and having the
draw go back to normal would make me think that the engine is too far
advanced. (If the engine fires too far advanced, the starter has to fight
the expanding gases in the cylinder.)
Based on what you have posted, I would two a couple of things
First I would check what it takes to turn the engine over by hand cold, then
warm the engine up completely and check it again warm.  If the engine is
hard to turn over by hand warm, you have a mechanical issue inside the
engine.
Then I would pull the #1 spark plug and bring the engine to TDC and verify
that the TDC mark on the dampener is in fact TDC.
Lastly I would check the draw with a different ammeter.
$0.02
Rick

On Sun, Apr 6, 2008 at 7:34 PM, Valda and Merl Rosenthal <mvrose at charter.net>
wrote:

> I have an problem with my starter on my 1980 MGB.  When the engine gets
> warm
> my starter struggles to turn it over but always starts.  I had it tested
> while
> it is struggling  and the starter draws 500 amps.  When the engine is warm
> and
> I pull the positive wire off the coil and crank the engine the starter
> works
> fine.  This is a new engine with about 600 miles on it.  I have tried 3
> starters on this engine and they both do the same thing.  And the problem
> also
> existed on the engine before my overhaul.  I have SU HS4 carbs, electronic
> ignition, and no pollution devices. My timing is set at 15 BTDC but have
> retarded it all the way to zero and the problem exists.  My valves are set
> at
> .013 (warm) and plugs are gapped at .035.  I have replaced the cable from
> the
> starter to the battery and the ground from the battery to the battery box.
>  My
> transmission and engine ground are new and connections clean.  Has anybody
> experienced a similar problem?  Any advice would be appreciated.
>
>
> Merl Rosenthal
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