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Motorcycle Repair/yamaha fz750. 1986


HI,I have a 1986 yamaha fz750 from california. I have just de-restricted the exhaust and re jetted the carbs.It ran ok before but now i have no power to the coils at all. I have tried everything i can think of, even tried another ignitor box.How do i check the pickup coils @ what should the risistance be. any other ideas will be a big help. thanks, Tony.

Hi Tony,

In my experience the ignition coils should have battery voltage
to them on the red/white wire.

This comes from a fuse powered by the ignition switch.

The engine stop or kill switch and the side stand switch
may also prevent either power flow or may ground
the ignitor.

Make sure you are getting over 12 volts to the ignition coils.

Next you can check the pickup coil has about 135-165 ohms
NOTE: (This might be 190 ohms before 1987)
usually between a gray and black wire. Gray is positive.

NOTE: (might be orange and black wires before 1987)

If you have different wire colors these specs may not
be accurate but should give you a starting point.

Let me know if you have questions about all this.

Keep the battery charged up to supply lots of current
to the ignitor.

Engine stop switch may break the power to the ignition if
it is faulty or ignition switch as well.

Wayne S.

Motorcycle Repair

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Wayne S.


Licensed Motorcycle Mechanic, Knowledge of motorcycles from 1960 up, Japanese, British and most other brand motorcycle repairs.


Worked for Yamaha, Honda, Suzuki, Kawasaki British: Triumph, Norton, BSA Other: Most Scooters and Mo-Peds

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