VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 Late 1927 Semi-Automatic Distributor

Well I am concentrating on my '27 Cabriolet again. Problem: It fires and runs about 5 seconds and dies and occasionally backfires. When I bought it it was not running. I have cleaned and gap checked the Champion W16Y spark plugs, cleaned the carb and jets , installed a modern coil with internal resistor, polished the spark plug wire (both ends), trimmed ends and made sure each wire was flowing current , checked for spark in each wire and each had a spark, I cleaned the points (which looked good, checked the point gap and set at .018 -.025, inspected the dist.cap,cleaned it,used a battery charger to make sure I had good current going in,primed the carb with gas and used a little starting fluid, turned the grease cap down, etc.
My main concern now rides on Service News 1927 July vol. 1 #7 p.27. I set the flywheel on 25 and my distributor is 1/4 rotation more,clockwise, than the illustration shows. Should all semi-auto. distributors point as the illustration shows, when set on 25??
Any ideas as to where is the best place to start searching??

Your symptoms would indicate a fuel problem. Perhaps the fuel not turned on at the vacuum tank? Float not set correctly? Needle valve stuck?

I think you can eliminate an electrical problem.

Thanks, I remember having trouble with the needle valve wanting to fall out, so I bent the tang some and it still seemed to want to hang.

Remove the float by removing the pin. Careful, you may loose the needle. Remove the needle if hasn't come out all ready. Check the end of the needle and if it isn't metal, it will have a black end and I would replace it with a full metal needle. In any case, clean the end of the needle carefully. Also clean the sides if it appears fuel has left a residue.

Reassemble, and give it a try. Did you turn on the fuel at the bottom of the vacuum tank?

Keep us posted.

Is the condenser grounded??

Don't you need a coil without an internal resistor for six volt systems?

No! If you were using an original coil you would use a resistor. So, with a modern coil, same thing. We need the resister and the fact it is built in is a bonus.

I'm confused. What is the purpose of the resistor? I don't think I have one.

The resistor keeps the coil from overheating at very slow speeds. If you are using an original coil you will need the round resistor that sits on the top. If you are using a modern coil you should purchase a coil for the 1954 Chevrolet. This coil has a resistor built into the coil so you don't have to worry about it.

I just did some reading on the internet on this subject. This is discussed on a lot of old car and tractor forums. My understanding is that the resistor reduces the voltage to the coil. For a 12 volt system, the coil would receive 12 volts when starting (curent bypasses the resistor) and about 7 volts while running (the resistor is now in the circuit)thus reducing wear on the points. The same logic doesn't seem to apply to 6 volt systems since then you would be running with about 3.5 volts which should give you a very weak spark.