I have a 1947 pick up with a 59 A-B flathead. the motor would run with a miss at Idle, and break up badly when attempting to raise off idle and accelerate. I figured the thing to do would be a basic tune-up. So I set about installing new points, condenser, plugs wires and the end culprit, a new rotor. Upon finishing, what I thought would be, the fairly strait forward tune up, I was rewarded with no spark whatsoever. I pulled the condenser strap to check it, still nothing. I opened the cap and the rotor fell out in two pieces. I have no idea what caused this, the rotor does however appear to be slightly longer than the original pre tune up rotor. At this point I figured "screw it" and threw the old one back in, still no spark, but when I opened the cap again the old rotor had not broken in two. plugs gapped at .30, points gapped at .16. I did pull the distributor to install the points but it went right back in the way it came out. Any thoughts would be greatly appreciated fellas

 

Giving you a bump to the top. Did you find anything out about your rotor issue?

 

Well after the rotor broke I stuck the original back in, but still no spark, I really am at my wits end.

 

i'd start with the basic stuff..test all connections..check the insulator in the dizzy body where the point wire passes through..check wire from dizzy to coil..primary power wire to coil ect..all are subject to failure from heat and vibration..i've had wires that looked and felt fine that had breaks mid wire that only showed the break once the insulation was stripped back..

 

Have a look inside the cap. The broken rotor had to run into something and it might have knocked the carbon off for the coil wire.
I don't guess you can see the points working and sparking with the cap off can you? You know, spin the motor and see if it arcs at the points.

 

after a significant stay in the hospital I am back tinkering with the truck I really can't spend much time on it before having to sit a spell but I got the distrib out of the truck and it does not spin as freely as I would expect. shouldn't it spin like any later model or is it supposed to be stiff enough to need pliers to spin?