Good Spark ??

[Cal Price]

OK, starting problems with the antique Yamaha. Plenty enough battery to turn her over well enough but often it just won't start.

Put the battery on charge for an hour or so and off she goes. My conclusion is that the spark is poor and only good enough when battery is fully charged, being a second "project" bike it does not get enough riding. The plugs are about six months old, recently cleaned and gaps reset and when left on the fins a spark is visible, does not look spectacular but how would I know.

One of the cylinders runs a little rich but not too bad, when battery fully charged she will start with only one plug connected so I guess the spark is good enough.

Is there a test for spark strength? Could I need new leads? any ideas folks??? Once going she runs well (for an '81) These bikes Yamaha XS series twins did not have a great reputation for starting.

[scratch]

Starter brushes could be loosing their effectiveness due to build up that requires more battery juice to 'jump' the resistance.