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View Full Version : 85 250sx No Spark, Replaced/Measured everything



lowtoe
07-10-2023, 04:32 PM
All the resistance at the CDI etc. checks out. Done all the test the service manual says to do, and replaced numerous parts. One thing I have found is that while my pulse generator resistance is correct (300ohm ish), I don't get any voltage when I try to start it. The forum post here - http://www.3wheelerworld.com/archive/index.php/t-185320.html says that you should get .5ish volts when cranking?

Does that mean my pulse generator gap is bad?

Thanks

poppa
11-09-2023, 08:49 PM
Did you check your wiring ? A bare wire may be grounding out

ATC King
11-09-2023, 11:14 PM
You can't test the CDI by the resistance values. It just doesn't work, event though it's in the repair manual.

What exactly are the 'numerous' parts you've replaced?

New can mean Never Even Worked, and worse than that is the Chinese variable. You can shoot yourself in the foot with the parts canon.

Yes, the pulse gen should create a low voltage. That's the best way to test them because even if they pass a resistance test, they may not do that when hot, or even create any voltage, which is how they are supposed to work.

lowtoe
11-21-2023, 05:28 PM
Sorry I thought I replied to this. It was a bad CDI. 2 brand new Chinese CDI's caused me months of headache -.-