Looks like I fried the optical sensor in my Mallory. Did some timing work, shut it down, then went out a few hours later to go for a drive. No spark. Put my old 009 with pertronix back in and its running.

Questions -

1) I have a bosch blue coil, and its measuring 3 ohms pos to neg, and 8k coil wire to either neg or pos. This seems a little low. Could it have been the cuplrit in killing my dizzy?

2) From what I have read, the blue coil has an internal resistor. Would adding a ballast resistor provide additional protection to the Mallory(once fixed) or would it just run like crap?

What do you have for ignition wires? Unilite module failure on shutdown is usually from using solid wire core ignition cables. Mallory specifies carbon or spiral wound wires several places in the instructions.

Pretty sure they are basic plug wires. Got a good source for spiral?

Try these guys:

http://www.jegs.com/i/Taylor/895/35891/10002/-1

Or go to www.tangerineracing.com

I ran regular bosch wires on my mallary unilite for years with no problems. I never blew a module (for like 5 years of running it) until about a year in running spiral core wires. I bought another module (made in China by this time) and blew that one, too in about 3 months. Bought another and blew that one, too. It seems to me the modules are disposable and they blow whenever they feel like it for no apparent reason. It got to be too expensive and now I am stuck with a 009.

This is good information, as I was almost going to buy one of these Mallory unilites w/vacuum advance. Do they make these with a magnetic trigger instead of the optical?

Nothing wrong with optical. I trusted one of these units for 10 years and 160K miles and never had an issue, even using the "wrong" wires.

What kills the optical units is improper voltage, a noisy signal, or a poor ground, or all of the above. I'll take optical anyway over a hall effects sensor.

here is some info from msd, I am sure they are promoting their product, but there is probably some truth in their info as well.

http://www.msdignition.com/uploadedFiles/M..._vs_optical.pdf

I have over 800 Mallory Uni-Lite equipped engines all over the planet. Of those I can count the failures of the optical pick up that have made their way back to me on one hand.

That includes running from Amsterdam to Beijing and from the northernmost tip of Africa all the way to the southernmost cape, mostly on dirt roads. Both those treks were with the same engine and the same dizzy, with no issues. Thats in a Type 4 application, as well.

Unless some variable imposes a collateral condition I don't believe the optical unit will fail.

Well that is a good data sample ...... what coil and wires do you recommend using with this Unilite ?

Magnecor are the best.

what about the coil?

Mallory components don't like MSD, Bosch or other coils. Keep all compatible components and you'll be a lot better off.

I've ran a few mallory's with a pertronix module, works good.
You can refit a old red cap points mallory with a pertronix. Way better than a 009, made in USA and cheaper than a new china mallory.

Another way to skin the cat is a red cap points mallory and a MSD, with this method the points are then a low volt trigger and they will never wear out.