Another Javelin question: starter motor

[nj-boatbuilder57]

The restoration continues!

This is my first electric start engine, and I am genuinely stunned to measure the starting current at 225A. Measured with a Fluke clamp-on meter and a known-good, strong battery (from my truck; my boat battery won’t turn the engine at all), the data is right there on the meter: 225A.

This is MUCH higher than a typical car starter, so I have to ask: is this correct? Or is this starter in need of rebuilding / replacing?

I’ve googled but can’t seem to find a definitive answer. Anyone know for sure?

Thanks!

[frankr]

I don’t know which specific starter you have, but looking at one in random, I see 170 Amps at stall test.

[jeff-register]

I’m with Frank,
Bad fields or shot bushings. Chevy used paper to insulate the fields, 1 rain & they are wet & decomposing, heavy draw, no magnitisun & less force, Yea I can’t spell. We are talking starters, right

[nj-boatbuilder57]

if LRA = 170A for this size starter, then FLA = 225A seems way wrong.

Are these specs published somewhere?

[jeff-register]

Na,
R.L.A.= running amp draw
F.L.A.=full load amperes & next is locked rotor amps & higher,
Friction is evident

[nj-boatbuilder57]

So what’s an appropriate replacement? The OMC part number from ’57 seems to be 376850, which (according to marineengine.com) rolls into several newer numbers, which fan out to dozens of different manufacturers’ offerings, ranging in price from $50 to $200. Sure seems easy to make a purchasing error.

Any suggestions?

[jerry-ahrens]

The Arco 5376 would be a good choice. I’ve put on a gazillion Arco starters, aternators and power trim motors, etc. never had a bad one. I often turn to them vs. OEM to keep the price down.
If I remember right, the Arco starter is physically shorter than some of the original OMC starters, but will work fine.

[frankr]

As you have discovered, there was a lot of evolution down through the years, and many newer starters will fit older motors. So, we don’t even know if your starter is original to the motor. 1957 was the first year for 12V starters, and the truth is they weren’t all that great. They were just adequate, and were easily damaged by stalling them or cranking for extended time.

I am presuming you may have the MDO which is where I got the 170 figure. But look at the difference between MCO and MDW specs. The MDW draws fewer amps but has considerably more ft/lbs of torque. Sorry, I don’t have a chart for newer models.

[frankr]

BTW, note that the specs are for 10 running Volts at the starter (4 V stall). In theory, at least, if you are supplying more voltage, like 11 V or more, the Amperage would go higher.

[Mumbles]

Before shelling out for a new starter, why not remove the lower end cap and check the condition of the lower thrust washer? If it is badly worn or missing, it will allow the armature to drop causing the commutator segments to short out to the end cap. Symptoms of this are a dragging starter and high current draw.

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