UK Karting - Notice Board (Combined Forum) : Re: coil testing?

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Re: coil testing?
Posted by 'SimonS' on 10 Jan 2015 @ 00:26

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SimonSJoined: December 2004
Total Posts: 4
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Looking at the Ignition diagram /parts list
(http://jagrotax.co.uk/wp-content/uploads/2013/11/Micro-Parts-List.pdf) the rotax has a CDI type ignition, (Capacitive Discharge) rather than a digital map ECU like the Selletra.

There's a good description of a CDI ignition at
https://www.youtube.com/watch?v=0yK3Opq_i0M.

You will realise from earlier posts that speed is 'the' factor in coil operation and the increase in speed of the engine causes the trigger coil to reach its trigger state earlier and thus switch the Silicon Controlled rectifier 'on' earlier BTDC.

Measuring the 'Reactance' in Ohms of the trigger coil and knowing the gate voltage of the SCR would allow you to calculate the difference in performance of various trigger and SCR combinations and select a combination which would give you a more optimum timing.

So you are half right, yes you could test the coil unit for the operation of the SCR , and half wrong, the important coil to test is the trigger coil, which isn't in the 'coil unit' at all but at the base of the engine.

Message Thread:

coil testing? by 'moondog78' (09 Jan 2015 @ 18:10)

Re: coil testing? by 'SimonS' (09 Jan 2015 @ 20:42)

Re: coil testing? by 'moondog78' (09 Jan 2015 @ 21:11)

Re: coil testing? by 'SimonS' << You are here!

Re: coil testing? by 'moondog78' (10 Jan 2015 @ 11:04)

Re: coil testing? by 'SimonS' (10 Jan 2015 @ 18:05)

Re: coil testing? by 'alanrr' (09 Jan 2015 @ 21:21)

sorry, coils not faulty by 'moondog78' (09 Jan 2015 @ 21:28)

Re: sorry, coils not faulty by 'alanrr' (09 Jan 2015 @ 23:36)

Re: sorry, coils not faulty by 'SimonS' (10 Jan 2015 @ 0:41)

Re: sorry, coils not faulty by 'Newjohn' (10 Jan 2015 @ 7:54)

Re: sorry, coils not faulty by 'alanrr' (10 Jan 2015 @ 21:49)

Re: sorry, coils not faulty by 'Howtogofaster' (11 Jan 2015 @ 15:17)

Re: sorry, coils not faulty by 'PaulMRotax' (11 Jan 2015 @ 22:22)

Re: sorry, coils not faulty by 'TeamPoor' (12 Jan 2015 @ 10:25)

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