i have an old 86' 250R with what i think is a weak spark, how would i test for a weak spark?

-eddie

 

Stick you tongue on the end of the plug wire and see if it hurts[img]i/expressions/face-icon-small-smile.gif[/img].


The best way is to check your coil and see if it is in limits. Check the primary and secondary. Also, check your plug cap. Resistor caps can go bad.

 

gee thanx but i think i won't try the tougue part, but what tool is used, multimeter?

 

Yeah a multimeter will work fine. Just put it in the ohms setting and check your resistance and compare it to specs.

 

Take of the spark plug, put it in the spark pulg holder thingy and then put the bottom about a few millemiters awayfrom the cylinder head and watch for a spark.

 

A multimeter that will measure ohms is what you need. Unplug the two wires going to the coil from the wire harness as well as unplugging the spark plug. Measure the resistance (in ohms) from one prong to the other (prongs that the harness wires come off of). This is the primary resistance. The secondary resistance is measuring from inside the plug cap to one of the prongs. Call your dealer or look in a shop manual for the proper specs.