When to run resistor??

I'm running a Mallory YLM distributor with an MSD Blaster coil and use a resistor. Its been working well for me since I swapped out my stock ignition system several years ago. I guess the answer to your question will depend on what distributor/coil you are running. Mallory does have a Q/A section on their web site.

It's whatever the coil mfg says to run not who made the points conversion. Are you having problems?

Whew, coil is definitely of unknown origin, original maybe? I can't seem to find a model of the Mallory distributor, just a long model number. I've always had a lousy idle. When I first bought the boat it wouldn't idle below 1000. Rebuilt carb (not me but a Holley shop).

After rebuild all was great but after 5 minutes or so of idling it'd start to chug, almost maybe not firing a cylinder? Dealt with it this way for 2 years bc rarely would we idle this boat that long so not much of an issue. During this time period it'd get hard to start if I shut it off. So then I found the choke was sticking. Put a new used choke assembly on, new plugs, wires, cap, rotor, all was great for ~35 hours.

Then one day when leaving sand bar carb acted flooded but no fuel too be seen, wouldn't idle for crap, but ran great when giving it the go go juice. Took it to Woody, cleaned plugs, minor mixture adjustment and started to idle and crank good so we left it.

About 15 hours later (this am) upon easy take off it missed, and missed a few times around 26-28 mph. Give it the go go juice harder and no problem. Skied some am and despite the boat not running top notch, it wasn't bad enough to not ski. Came home, put a spare set of autolite 24's in, stuck the time light on it and all seemed ok. Skied this pm, ran lil better, just a miss on easy take off, hard take off no problem. Normal chug idle was present as it basically has for 3 years. I didn't think the resistor would cause this just thought I'd ask why it's there on electronic. The dizzy modules usually work then just up and die, correct? Probably gonna order a new 4160 first of the month, it's time to retire my '73 model Holley. If that doesn't cure it then I'll have to focus on ignition.

Is your distributor a 2 wire or a 3 wire?

It's a 3 wire. I double checked the ground making sure it's clean.

HW, how's that a lot of parts to change? Just a distributor and carb.

Also since all this I caught the carb flooding so it's time to replace. Ordering it when I get home. install & hope it cures the problems.

Nice Schematic Brian.

Thanks Zach, although I can't take credit for that truly artistic work.

Todd, well, the red wire actually is seeing the full 12. Those electronic conversion kits do take the resister out of the equation, that's why they often raise hell with the old, original coils, that all of a sudden seeing more voltage after the conversion.