Motorcycle Repair: 1986 yamaha FZ750, coil works, pickup coil

Question
Hello, I am having a problem with getting the left ignition coil 1&4 to get a spark. I am getting power to both sides 1&4 - 2&3, coil 2&3 is working fine. Any help or advice would be so appreciated. Thank you for your time and expertize!! Neil

Answer
Hi Neil,

Have you tried switching the wires to see if
the 1/4 coil works when attached to the 2/3 wires?
If the 1/4 coil won't work on the 2/3 wiring
then the coil is likely bad.

Also if the good 2/3 coil won't work
on the 1/4 wires then you have
problems with the 1/4 circuits.

This could be the ignitor is
not triggering power in the ignition coil
or it could be a pickup pulser problem
if you have two pulse coils.

I think you may only have one on that
model although it has a cam pickup and
a crankshaft pickup coil.
The crankshaft pickup or pulser is often
the one that causes spark problems.

Often the problem is just poor connections
or a bad plug cap.

The ignition coils are triggered
by the ignition module or ignitor unit
grounding the coil at the correct time.

The battery usually is the source
of the current for the ignition coils
and needs to be strong.

The ignitor timing is handled by the pickup/pulse coil.
It tells the ignitor when to ground the ignition coils
so they spark.

Start by doing a coil switching test.
Once you know if it is the coil
or not then you can check the 1/4 wires, plugs
and other ignition parts for poor connections
or problems.

The pulse or pickup coils can be tested
for an ohm reading. The wires will
usually be under the left side cover.
The pickup coil is in the left engine case.
The wires are usually orange/black or gray/black.
Ohms are about 120 between the wires when disconnected.

The ignitor plug could be checked for bent
or corroded pins.
Check for broken wires and use "Deoxit"
or good quality electronic cleaner on the
connectors.

The coils may need to be removed and grounds
checked if they ground on the frame.

The main ignitor unit is the one part that
can only be cleaned etc as there
is no reliable test for them.

Good luck,
Wayne S.
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