[Mgs] MGA Points

Barney Gaylord barneymg at mgaguru.com
Sun Sep 27 22:07:06 MDT 2009


At 09:47 PM 9/27/2009 -0500, Robert J. Guinness wrote:
>I have had to replace the points on my MGA's distributor after only 
>3 months of service (less than a 1,000 miles).  Apparently, the 
>rubbing block wore down so that the points remained closed.  The 
>points could not be adjusted to increase the gap because they were 
>already fully adjusted out. ....
>--

I had that problem once about 20 years ago.  In the middle of a long 
road trip I had replaced the ignition coil, and the problem started 
immediately thereafter.  I was driving more than 2000 miles per week 
on that trip, so the problem would reoccur every few days.  At one 
point I used large side cutters to notch out the slot for more 
adjustment range.

After returning home I discovered I had installed the wrong ignition 
coil, one intended for use with ballasted ignition system, half the 
resistance, twice the current with no ballast resistor.  Apparently 
the excess current would overheat the points and melt the rubbing 
block.  These were contact points with the red plastic rubbing 
foot.  Points set with phenolic rubbing block is more heat 
resistant.  Check resistance on the primary of your ignition coil, 
should be about 3.2-ohms (slightly lower for high energy coil).  If 
it measures around 1.6 ohms, see how far you can throw it.

Barney Gaylord
1958 MGA with an attitude
http://MGAguru.com


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