billsfan60 1 #1 Posted April 14, 2012 Just did a rebuild on my K241. The thing runs great except for one issue. After about three hours of break in running it started backfiring and died. Once I got over the heart attack it caused I started checking things out and found the points had closed up. No biggie, it's happened to me on my MGB. I reset them and it did it again two more times. I took a closer look and found the points had melted. I had a spare set so I replaced them and ran for a short period of time with no issues. Don't know if it was defective points or an issue with the rest of the ignition system or, even though I was real careful with the rebuild maybe I got the timing off by a tooth. Share this post Link to post Share on other sites
wallfish 15,919 #2 Posted April 14, 2012 I think they do that when the gap is real wide. :confusion-shrug: Share this post Link to post Share on other sites
Save Old Iron 1,563 #3 Posted April 14, 2012 Replace the burned points with a new set and replace the condenser before running the engine with the new points. Confirm the condenser ia actually grounded to the electrical system. An ungrounded condenser cannot function in the ignition system. One of the many functions of the condeser is to act as electrical "shock absorber", to prevent the points from arcing as they open. Excessive arcing is most likely the cause of melting the points contacts. A closer look at the contacts may show material from one contact is being transfered to the other contact. Also, be sure you have the coil wired correctly. Battery power to the (+) on the ignition coil. Points and condenser wired to the (-) coil terminal. Share this post Link to post Share on other sites
Anglo Traction 759 #4 Posted April 14, 2012 Your Condenser could also be good!, and the Ground is not good on it. It could effectively bypass the Condenser's function. Share this post Link to post Share on other sites
Save Old Iron 1,563 #5 Posted April 14, 2012 Confirm you are using a 12 volt coil with a primary circuit resistance of approximately 3 - 5 ohms. A coil intended for use in capacitive discharge ignition systems usually have a very low primary resistance and will overload the points in standard points based systems. A quick resistance check from the coil (+) to (-) terminals should read between 3 - 5 ohms. A capacitive ignitioin system coil will read lower than 1 ohm. 1 Share this post Link to post Share on other sites
billsfan60 1 #6 Posted April 14, 2012 Thanks guys, will be checking all the above in the morning. The new points arrived today and I'll put them in only after the problem is corrected. Share this post Link to post Share on other sites
Wheel-N-It 2,967 #7 Posted April 15, 2012 Confirm you are using a 12 volt coil with a primary circuit resistance of approximately 3 - 5 ohms. A coil intended for use in capacitive discharge ignition systems usually have a very low primary resistance and will overload the points in standard points based systems. A quick resistance check from the coil (+) to (-) terminals should read between 3 - 5 ohms. A capacitive ignitioin system coil will read lower than 1 ohm. lean heavily on this advice. Van Share this post Link to post Share on other sites
