Coil voltage

[kurt112345]

Quick question on coil voltage, my battery has a new bike master gel battery and is 13.2v, at my coils is 11.5v. Could this create a running issue or miss? Has anyone ever done the coil relay mod that is common practice over at the GS forum, by using the original coil power wires to trigger a relay that sends direct battery voltage to coils.

[djalbin]

The original battery spec for the bike is 12V 14AH> The charging voltage, as measured across the battery @ 3K RPM, should be between 14.3V and 15.3V All the other electrical spec, repair, maintenance information refers to continuity or resistance measurements and don't list the voltages.
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[DonTZ125]

11.5v at the coils can certainly cause misfiring and plug fouling. Before you go running fresh wiring and splicing in relays, check the various connectors and wires for corrosion and other damage. Sometimes it's easy to fix; sometimes it takes a little surgery.

[TomcatMJ]

Check the resistance of the primary side of the coils (the side connected to the tci), as a wrong resistance value there might pull down the voltage, too...and if the coils are out of specs, then its time to exchange them...or the right point to change to single coil usage (pairwise serial connected coils with half the resistance of the default of original one coil, each )...

[kurt112345]

The 11.5v I was getting is with coils not plugged in red/white wire, and did check coil resistance while I was there and both within spec. Looked at diagram and chased the red/white wire around, used electrical cleaner and small diamond file to clean connectors. So far I cleaned the start switch took it apart cleaned contacts and it's connector in the harness. Cleaned ignition box connectors, cleaned where it goes in to fuse box put a new fuse in just cause. And cleaned some relay where that wire goes into. No change of voltage. Iam I missing something?

[TomcatMJ]

If primary coil resistance and secondary is ok and the spark plug connector and cables are ok, then it should work as expected. If its not working as expected, then check if you´re using original spark plug connectors or some with a higer resistance than the originals in the connector itself, as this might lower the power of the spark if the connectors resistance is higher than usual (but it should do its job then anyways, just with a little less radio-interferences, as lowering these interferences is the reason for 10kOhm connectors instead of 5kOhm connectors )....

[kurt112345]

The plug wires and plugs arent in question, the problem is when you turn key on that there is 1.5v drop from 13-13.1v at battey and 11.5v at coils. Iam under the impression they should be the same within .5v. So somthing is creating a little resistance for the coil power wire.

[TomcatMJ]

Check the tolerance of the multimeter you use in the according manual
Some cheap ones have tolerances of around 5%of the actual measurment-ranges topvalue +/- an absolute value of 2 at the last digit...not that you´re just stumbling in a most times ignored stadard-tolerance-trap of your measurement-tool