Bench testing a 1932 - 1939 starter motor

[John Mason]

Hi all, Can anyone tell me how fast should a 1932 - 1939 starter motor spin when bench tested using a fully charged battery and jump leads. I know the importance of getting good connections between the battery and starter motor. Also should the pinion return down the shaft to the 2 clawed spring when the power is switched off. I suspect that mine is not spinning fast enough to make this happen although I have cleaned it all in petrol.

John Mason.

[squeak]

John I believe the pinion has to be kicked back into the clutches of the "claw" spring by the ring gear when the motor fires.

[Ian Williams]

Agreed Russell, John if your starter spins fast enough to throw the pinion out so it engages with the ring gear it should be fine

[Tony Press]

John I believe the pinion has to be kicked back into the clutches of the "claw" spring by the ring gear when the motor fires.

My thought exactly !

[Bob Culver]

Is is the accel wot matters rather than speed. The starter accelerates violently and needs be held in a vice. The spring clip which lightly grips the pinion is critical; if too tight pinion will not engage and if too loose will not retain pinion. It will then drift into mesh and then so violently out of that the process often repeats a few times before it chances to return sufficiently gently not to rebound. Curious and puzzling sound effects.  When the engine fires the overrunning  returns the pinion but not too forcefully. (written before others appeared)

[John Mason]

Thank you all. The starter appears to work fine then. I will get it back on the car.

John Mason

[John Mason]

Final update regarding the starter motor on my Ruby. My son has been over this morning to help me sort out the Ruby and put things back together. Although the starter spins off the car once back on and engaged with the flywheel refuses to turn the engine. I am now in the predicament. Is it the starter or the battery that's had it ? At the price of a recon starter I Am wondering if I need to check it again on a known good battery.

John Mason

[David Stepney]

If you have access to a multimeter or voltmeter, check that the battery has 6.3 volts or thereabouts. This will mean that itv is fully charged.
Next, turn on the headlamps and engage the starter. If the starter does not turn and the lights dim to a glow, then it is probably the battery.
If the lights dim only slightly when the starter is engaged, it is probably the starter. The most common starter problem is with the brushes.
I assume that the engine turns freely on the starting handle.
Hope this helps!

[nrzam]

On Ruairidh's advice I now have an additional earth strap direct from the battery to the gearbox. The starter motor used to be very sluggish but is now very keen!

Ian