djbragg wrote: I have a 1976 KZ900 with dyna s and 3 ohm coils, coils go to 5 ohm when heated with hair dryer, is this normal?
It is normal for them to go up by some amount, but 5 ohms seems a bit much. I would have expected closer to 4 ohms. There are a lot of variables, though. For one thing, how accurate is your meter?
Here is a link to some data on typical Kz coils and how they respond to heat.
s3.amazonaws.com/gpzweb/Ignition/Ignitio...s/IgnitionCoils.html
Assuming you have the large, green Dyna 3.0 ohm coil,
I found on a very similar, 3.0 ohm Accel Supercoil, with self-heating from use, would raise the resistance from 3.2 ohm cold to 3.8 ohm hot. That was in open air, not moving.
A hair dryer might heat it more if it's really close maybe. And in normal use, when mounted under the tank on a really hot day with stop and go traffic it may get hotter than my test. I was only demonstrating that the resistance goes up significantly, but not really tracking the temp versus resistance.
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