V7 Left Ignition Coil Resistance

[organfixsing]

Anybody know the resistance readings for primary and secondary coils on a 641901 ignition coil (Left cylinder part # 641901). Mine appears to be faulty with intermittent sparking.
The Primary reads 0.6 ohms and the Secondary reads infinity or perhaps I am measuring it wrong?
Any help appreciated.
Cheers
Brian 

[RinkRat II]

  Rule of thumb...Primary resistance 1-5 ohms checked between pos and neg post, coil disconnected
                           Secondary resistance   7500-10000 ohms check at either terminal to plug post
                       Plug post to ground.. Infinity
             Hope this helps
                Paul B
             

[organfixsing]

Yeah, thanks Rink. Much as I expected. Apparently I have an open circuit in the secondary, but, sofar, it works a lot of the time.
I have been chasing the cause of black soot on the back end of the exhaust pipe (left pipe only) and have replaced, in this order, spark plug connector/boot, spark plug, plug lead so this only left the HT coil, the crank position sensor and the ECU. Hopefully the last two are OK.
I have a couple of second hand units which should lob here about the middle of July hopefully.

Cheers
Brian 

[Kiwi Dave]

Are you able to swap the coils over to see if the issue moves to the right?

[organfixsing]

Kiwi, the coils are different between left and right. The right coil has an internal switch arrangement and has a 3 pole connector while the left coil is more of a standard coil with 2 pole connector and the switching done directly by the ECU.
The reason for this is that the MIU G3 was originaly designed to be used primarily on single cylinder engines and the use on a twin cylinder is a bit of a kludge, consequently, there is only one heavy duty switch for the ignition coil from pin1 of the ECU which is designated 'Cylinder Coil Command Output 1 (LH)'.
The right coil is supplied with battery from the 'Injector Load Relay' and a permanent earth (from ECU pins 7 & 23) and the switching for the coil comes from ECU pin 8 which is designated 'Cylinder Coil Command Output2 (RH)'.
All very straight forward I don't think.
A bit hard to swap them
Thanks for the suggestion.
Cheers
Brian