spark gs400

[Jay2903]

Hopefully the last post on this one.
Its a gs400 that im trying to get running. ive checked all the wiring + connections + grounds, battery is good, new brushes in the starter motor, switches seem fine. cranking voltage almost 10v. rectifier, pickup coils and stator checked/tested. New ignition coils + new fuse.

Theres two suspicious things. For the right coil I measured about 12v on the + and - cables that go to it.
On the left coil there was 0v for the + and 12v for the -

Second thing- the left ignition coil heats up after a few minutes.

Wiring diagram - https://s61.photobucket.com/user/Jay29031/media/gsx400_zps9n5bbmlw.jpg.html?filters[user]=145531479&filters[recent]=1&sort=1&o=1

my diagram - https://s61.photobucket.com/user/Jay29031/media/IMG_3027_zpsws7xpbui.jpg.html?o=0

Any help greatly appreciated

[Jay2903]

Anyone got any ideas ?

[uberkron]

I would guess your igniter, if not points have failed. What year?
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i ride a zip 50 2smoke. It overtakes a hundred times a day.

[bikenut]

Or could you increase voltage across battery when cranking by using the assistance of a good fully charged car battery??

Battery dependent ign system which may "drop out" due to insufficient battery "energy" when cranking.

As to a coil getting hot, is that the one that makes a spark. Do both coils make a spark?

How was "trigger" res values one compared with the other??
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nuts about bikes

[bikenut]

Is the starter button a combined starter/ign kill type??
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nuts about bikes

[bikenut]

Also could you increase voltage across battery when cranking with the help of a fully charged battery, ign system looks as if its battery dependent and may "drop out" due to insufficient "power" when engine is cranked.
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nuts about bikes

[Jay2903]

[Jay2903]

[Jay2903]

[Jay2903]