weak spark 1991 KTM MX300

I can't get my bike to fire up. Spark is weak. What should the output voltage be at the stator on a decent kick? What should be the voltage output at the plug on a good kick?

Many thanks!

Cann't tell you the voltage but you have the old SEM ignition which was prone to failure. Start with replacing the coil if that doesn't work then the stator.


I have figured out the problem and I want to post this very important information. If you have weak spark or no spark do the obvious and verify all wires are connected and clean then check the leads on the stator.

On the SEM stators 1991 - 1996/7 they were prone to failure and I mean more freaquent than a flat tire so thest the following leads from the stator:

Black/Red 1.7 KM ohms (or 1700 if you have a digital)

Blk/Green 165 ohms +_ 20

Green/Red 1.7 km ohms (or 1700 if you have a digital)

Yellow to yellow 1 ohms

My reads were as follows: B/R 1728, B/G 171, G/R 1900 and Y to Y -infinity

Coils do not go bad that often even though the CDI is intergrated into the Coil..trust me I spend 175.00 on a new coil and it wasn't the skoking gun. By the way the coil is for sale...cheap.


so you bought new parts without testing the old ones first ??????????

that was some damn good advice you gave him ktmfred :lol::lol::ride:

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