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spark troubleshooting


Checking for Spark on a Coil, Points, and Condenser System

Most people replace the coil first because it is easy to replace,  but seldom the problem.  Below are a few tech tips to help
 determine the issue.

1) Check  the gap of your plug and/ or  install a new plug to eliminate the  plug  as an issue in the system-- gap 35-40 /1000th
 on the new plug.
2) Remove cap from wire- wire should be able to arch a spark  approx 1/4 to 1/2 when held near the cylinder or cylinder head.
3) Check all grounds or bypass grounds- Mopeds, like older Tomos mopeds, do most of the grounding thru the rear taillight housing.
    Ground the blue wire to bypass this system on older Tomos Models and others to eliminate this ground issue.
4) Just because you have lights DOES NOT mean that the ignition is good--- lighting coil is a separate system and does not
 involve points and condenser.
    You will need a test light probe to test for a pulsed signal from the black trigger wire that  comes from the magneto to the coil.
        -This pulsed signal  indicates that the points and condenser are correctly functioning.  If there is no signal or a constant light
 on the test light pencil,
          you will need to remove the  flywheel and clean (nail file and electrical contact cleaner work best) or replace points
 and replace condenser.
         Pullers, points  and condensers  are listed at  our Points/Condenser Page
4) Use  threaded center puller to remove the flywheel as these are a balanced  precision item and a gear puller can bend or distort
 the the flywheel rendering it useless.
5) Adjustment
        -Point gap setting at 15-18/1000th
        -Timing adjustment by rotating the stator plate - only about 2 degrees of adjustment are possible and typically in the
 middle of the adjustment is closest to proper timing. For the enthusiast, typically points should open about 1.8 - 2mm 
 before top dead center.