MG Car Repair: 66 MGBGT ignition, positive earth, mechanical restoration

Question
just began mechanical restoration on a car that has not been on the road (or started) for almost 20 years.  Wiring appears to be ok but can't get spark at the plugs.  In addition the starter seems to turn slowly.  Cap is used(as are the points and rotor, but all seem serviceable with no corrosion and the points are gapped correctly.  Would like to keep it all original (including the positive earth), but am just about to give up and change polarity and go with modern ignition.
thanks


Answer
Hi Jim.  The GT was not made until the end of 1965, so a 1966 is a very early one.  It would be nice to keep it as original as possible.

There is no need to change polarity.  I would fit a Pertronix Igniter inside the distributor.  These are available with positive earth.  Also, I would fit a new set of plug leads (wires) and a new set of spark plugs (Bosch W7DP).  

The slow starter motor sounds like corrosion due to lack of use.  Take it off, clean everything and put it back.  Also, check both the earth wires for a good clean connection to the chassis (at the battery and at the engine mounting).

To check for a spark, pull the central wire from the distributor cap and hold it about 1/8 of an inch from the cylinder head.  Get someone to turn the engine over and look for a spark.