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1974 L48 - trying to work through a bit of rough idle and other timing and carb related issues. I figured I should double check my spark, here’s the result. I’m guessing I should replace the rotor, but I don’t see any other concerns. But I’m also not an expert:
I've seen far worse "wear" and/or burn marks on rotors, so in that respect, I wouldn't worry. On the other hand, where the plastic is melted over, to retain that contact, it looks a little questionable, and if the contact breaks loose, A) the car will stop running; and B) while the contact is thrashing around, for those moments before the distributor stops rotating, it could certainly mess up the cap, and maybe some of the other internal components in the distributor.
Short answer, it's not an expensive or difficult part to replace, so if it was me, I'd drop in a new one. The cap, however, looks to be in good shape.
Cap looks ok if you don't see any cracks in it...Just use some emery cloth on the contacts to make sure they are clean.
The rotor is a bit long in the tooth and shows some corrosion..You can try cleaning with the emery cloth or go ahead and replace...
Thanks for the $0.02 -- I also thought the cap looks fine. The rotor is what, a $10 part? I'll replace.
Helps to know it's also not so bad as to possibly cause spark issues.
Ck the length of the rotor tip. There are some shorter than others and makes a pretty big gap to jump. That ones looks to be getting a little warm. Ck plug wires also for high resistance.
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Hi again
Does your tachometer work?
I don't see a cable attached so you might have an aftermarket distributor installed.
Also, it looks like you have a pertronics (or similar) electrical ignition system installed. You might consider going back to points and condenser set up.
That is not the stock resister wire on the coil positive, does pertronics require full 12 volts?
Does your tachometer work?
I don't see a cable attached so you might have an aftermarket distributor installed.
Also, it looks like you have a pertronics (or similar) electrical ignition system installed. You might consider going back to points and condenser set up.
That is not the stock resister wire on the coil positive, does pertronics require full 12 volts?
tach works. Little jumpy vs a modern tach. But definitely works. I believe 74 is the last year of mechanical tach?
I also agree about the electronic ignition addition. I don’t know much about it though. Why would I go back to points and condenser?
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Originally Posted by Millie74
tach works.
That's good, I didn't see the cable.
I believe 74 is the last year of mechanical tach?
Yes, that's correct.
I also agree about the electronic ignition addition. I don’t know much about it though. Why would I go back to points and condenser?
Points need a resistor wire and Pertronics needs full 12 volts, it looks like that red wire works so leave the Pertronics installed.
If it ever fails, then you can decide what to do.
Pre HEI dizzy has the weights oriented the way you do.
Later when HEI came out, the weights are installed looking like the state of Florida.
Because you are technically NOT a Points-N-Condenser user anymore, I wonder if the weights should be flipped over?
Anyone? Anyone? Bueller? Bueller? Anyone? Anyone know?
(Likely not)
Last edited by HeadsU.P.; Sep 24, 2023 at 07:34 AM.
74 Distributor rotor wear
