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Trying to follow the starter mechanism on a 914 , I can see how the sprag  clutch works 

but can’t figure out what the idler gear does on the starter shaft , doesn’t seem to drive anything the small gear is engaged with the big gear on the crankshaft which locks when the starter is run then free wheels the gear behind that looks like it drives the cam shaft, what am I missing, Greg 

  • Re: Starter

    by » 5 weeks ago


    Hi Greg,

    I'm having trouble understanding your question, so I'll do my best to explain.  The idler gear is the connection between the starter splines and freewheel gear.  It's there to provide a gear reduction (and torque increase) between the starter and the free wheel gear.  Torque is transferred from the starter spline to the inner most teeth on the idler gear, then to the outer most teeth on the idler gear to the free wheel gear.

    Starter 9t to 50t (inner most teeth on idler) to 11t outer most teeth on idler) to 50t free wheel gear.  6300-6400 +/- rpm starter motor RPM to 250 rpm crankshaft


  • Re: Starter

    by » 5 weeks ago


    I understand the small gear is meshed with the large sprag clutch gear but it looks like there is another gear behind that small gear on the starter shaft, 


  • Re: Starter

    by » 5 weeks ago


    I understand the small gear is meshed with the large sprag clutch gear but it looks like there is another gear behind that small gear on the starter shaft, 


  • Re: Starter

    by » 5 weeks ago


    The gears for the starter are designed to give the small starter enough torque to turn the engine. A straight single geared small starter would not have enough torque to turn the engine. The starter interior top rpm is approximately 6200, but is geared down for torque and proper engine speed. 


    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell


  • Re: Starter

    by » 5 weeks ago


    Hi, if you require addition clarification, you'll have to provide some pictures.


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