Can someone help me with wiring?  I have an old Kolb kit that was never finished with a Rotax 503 and will have a radio (and want minimal interference).  I would like to use the correct gauge wires and use shielded where correct to do so.  Do you have any advice for the mag kill switch wires?  Rotax analog tach?   Being a 170 watt output stator, I was thinking of using 14 or 16 gauge unshielded to and from the regulator/battery (I have several, probably use Key West since I used one long ago).  I have purchased CHT and EGT gauge wires with extensions, so that is not an issue.  If unshielded, should I use MIL-W-22759/16?  If shielded, then what?


I am sure this is somewhere on this website and in the manuals, but I cannot find it.  Can someone point me in the right direction?.





  • Re: Help with installation wire type and gauge

    by » 3 years ago

    Bigger is better; to a point.
    Wire gauge will have two major criteria.
    It will need to be large enough to carry the current and not so small as to be fragile.
    14 AWG with a 20 amp fuse for the power wire cable would be a good choice.
    Nearly anything will work for the Mag Switches and Tach Signal, but anything smaller than 18 AWG becomes a little too delicate for the environment that it will be in.

    Mil-spec wire will be your call.
    Just be sure to fuse the wires at the source end with a fuse that is appropriate for the wire it is protecting.
    Assume one day it will chafe to ground and short out.  Maybe not in your lifetime, but assume it will happen eventually.
    18 AWG can handle 10 Amps but a 5 amp fuse might be more conservative.
    The Mag and Tach wires are not power cables and will not need a separate fuse as the ignition and tach circuits should already be fused.

    Bill Hertzel
    Rotax 912is
    North Ridgeville, OH, USA
    Clicking the "Thank You" is Always Appreciated by Everyone.

    Thank you said by: Dennis Urban, RotaxOwner Admin

  • Re: Help with installation wire type and gauge

    by » 3 years ago

    Thank you.  That is what I needed.

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