6 Volt Coil min voltage - Car not starting

[oldstudemike]

Whats the minimum volt requirement to the positive side of a 6 volt coil. I'm getting a very weak spark with a new coil.

Thanks for your help

[Mark Shaw]

http://vcca.org/forum/ubbthreads.php/ubb/printthread/Board/4/main/30907/type/thread

[JohnD1956]

Two things, What volt reading did you get on your coil positive wire? And how/ what makes you think the spark is weak?

[trini]

I guess the voltage you are looking for is the output high voltage from the center of the coil. If I remember it should be about 3000 volts max. The 12 volt coils should be about 4000 volts.(that is pre electronics days) If your voltmeter can read that high get an assistant to crank and you set up the meter. It should register a voltage. I usually check 12 volt coil by hooking it up to a battery on the bench. Quickly touch the battery wire to the coil. The spark is a loud click. This is not so with a 6 volt. I am currently having the same situation with my 28 Senior 6. With a brand new 6 v Echlin coil I tried the same test and barely got a spit. I think all 6 volts operates the same way but they fire the plugs. My Echlin replacement is working fine. Cheers and good luck.

[Dandy Dave]

With the switch off, do an olms test. One test wire to the negative side of the coil. One wire to the center coil tower. You should get some kind of a reading. If it comes back 0.00. There is a break in the secondary winding and the coil is junk. Are the points old? Points oxidize, sometimes between where the platinum plating is affixed to the arm. This will also give you a weak spark. Could also be a bad condenser that is nearly shorted. Also I have seen bad ignition switches that do not make a good connection internally. If the spark is weak and yellow, you definitely have a problem. If it is early, it may also have a resistor in the line. That could also be faulty. By the way, what are you working on? Dandy Dave!

Edited July 4, 2014 by Dandy Dave (see edit history)

[trini]

Hi Dave , I am working on a 1928 D.B. Senior with a 6 cylinder engine. the original coil tested open. The pigtail wire from the "in" terminal inside the distributor burnt out, so you know what that means, "shorted condenser" I replaced the coil and condenser and fixed the pigtail. The engine is running rich with lots of white smoke and the tailpipe is slightly oily. That oil is what I put in the cylinders to free it. Lots of it. The carburetor needs setting up right. It is a Carter B.B. 1. When I get that done I will run it for about an hour and a half to burn of all the oil I put in and also residue on the exhaust and elsewhere. What bothers me now is the oil gauge registers 50 and the needle shoots up to maximum 50 this evening when I ran it for about 5 minutes. Before that it was 30 pounds, then 40 pounds and now 50. There are no resistors any where, Not even a safety fuse. Cheers and have a nice day.

[Dandy Dave]

Talking with an acquaintance a number of years ago, that early 6 Cylinder flat head had problems with vapor lock with this alcoholic gasoline we have now. Something to think about. Dandy Dave!