Running Rough: Dizzy questions (pics)

[NC Rover]

So I cranked up the rover the other day and it was running rough with some black smoke coming from the exhaust. It never does this. Smelled like it was running rich. So I took the dizzy cap off and it looks as if it is misfiring. (Note: I am running a Petronix igniter...no points).

I also checked the plugs and they smelled like gas.

Obviously it is running rich.

Questions:

1.) Could I slightly rotate the dizzy forward/backward to prevent this or is this something regarding the carb? I've been running the same carb and dizzy for over a year now with no problems until recently.

2.) In which direction does the arm on top of the dizzy rotate...clockwise or counter-clockwise?

Sorry for the stupid questions.

[Apis Mellifera]

First, it's time for a new distributor cap and rotor. The cap has a carbon build up, which can cause arching which can lead to a misfire. A misfire can cause unburned fuel to collect on the plugs. Arching can also produce a weak spark, leading to poor combustion. To put it in the simplest terms, the electricity leaves the coil, goes int the center of the dist. cap, the rotor routes the electricity to the right spark plug at the right time. If something prevents some or all of the electricity from making it to the spark plugs, you can get the symptoms you describe.

The rotor spins counter clockwise.

Rotating the whole distributor will change the timing. An out of time engine will also produce poor running, loss of power, but generally you can't get keep it running and also get it far enough out of time to blow black smoke and get raw gas on the plugs. A stuck choke certainly will do that.

[I Leak Oil]

I second the new cap and rotor but this sounds like a fuel problem to me. Which carb. do you have? Zenith?

[NC Rover]

I second the new cap and rotor but this sounds like a fuel problem to me. Which carb. do you have? Zenith?

I will swap these out.

I have a Weber DTML double-barral.

[Apis Mellifera]

A Weber certainly can be a temperamental carb, but I'd expect the plugs to be sooty if the carb was causing the problem. Plus, the onset was sudden. Generally, you'd have a chronic problem if the carb was over fueling. Raw gas on the plugs means they aren't firing or aren't firing well. I'd still focus on ignition.

[NC Rover]

A Weber certainly can be a temperamental carb, but I'd expect the plugs to be sooty if the carb was causing the problem. Plus, the onset was sudden. Generally, you'd have a chronic problem if the carb was over fueling. Raw gas on the plugs means they aren't firing or aren't firing well. I'd still focus on ignition.

Here are some pics of what the plugs smell like. Now that I think about it, the exhaust has been smelling a bit rich lately...but I've never had any running issues. It happened after a cold start one day. Just instantly started running bad. I'm definitely going to replace the cap and rotor as well as the plugs to be on the safe side. However I guess I'm trying to find out what caused this in the first place: Carb or Dizzy or both combined.

[NC Rover]

The cap has a carbon build up, which can cause arching which can lead to a misfire.

Rotating the whole distributor will change the timing. An out of time engine will also produce poor running, loss of power, but generally you can't get keep it running and also get it far enough out of time to blow black smoke and get raw gas on the plugs. A stuck choke certainly will do that.

I checked the choke...definitely not stuck.

The whiteish haze on the inside of the cap was the part of the cap that rests against the magnet.

I never had any loss of power or smoke from the exhaust leading up to this. As soon as I cold started it, I noticed it running rough with a bit of black smoke....not a lot but you could tell it was coming out.

[jac04]

From the looks of those plugs, you have been running rich and/or have weak ignition.
Google "reading spark plugs" for a wealth on info on what the plugs can tell you.

http://www.aa1car.com/library/sprkplg2.htm

[NC Rover]

From the looks of those plugs, you have been running rich and/or have weak ignition.

I know the Jacobs Ignition and Super Coil are working fine. The Petronix ignitor is new as well. Plug wires are brand new.

I'm guessing there is something small that is causing this rich mixure. Maybe carb needs to be adjusted? Dizzy adjusted?

I'm going to replace the plugs, cap and rotor. Hopefully I can solve the problem.

Thanks again to all the suggestions/information.

[Nium]

The carb shouldn't be adjusted till the ignition system is solid. Since your cap is burned definitely do not adjust the carb till the new cap, rotor, and plugs are in. Looking at your pictures of your distributor cap my 2 cents would be that the cap is the cause of your issues and as others have said electric issues happen all of a sudden.



The areas of the cap I circled in red have been burned away. Compare it to your new cap when you get it and you'll see what I mean. Once you get the new ignition components reset your ignition timing as it's probably off.

Has anyone else seen a cap burn like this? It's a first to me.

Cheers!

[bkreutz]

That looks like the timing is a bit too advanced, normally the spark would jump when the rotor is aligned with the center of the post. (this is assuming my mind is visualizing the rotation with the cap orientation correctly) so it could be too far retarded if I'm wrong. (CCW rotation should look like CW rotation when viewed from an inverted view). (I think). Anyway I think you get the idea where my thinking is going. It also looks like there's more spark voltage than that cap is designed to handle. Are you using a Pertronix high output coil? Could be it's too much for the stock cap to handle. Just a couple of thoughts. HTH

[cgalpin]

If the rotor spins counter clockwise, don't those burn marks indicate that the timing was too advanced and the spark was firing early?

[stomper]

My cap looked very similar to this when I replaced it about 4 weeks ago. I am running a stock coil, but have an MSD ignition system installed by the previous owner. (It still has points, it just boostes the ignition current I believe) Since I time mine by ear, I assumed it was because I was running too far advanced, but it likes the timing I have it set at, and runs very smooth.

I'm anxious to hear how you get on with this after replacing the cap, rotor and plugs.

[kevkon]

Your problem may, as often happens, be a combination of things. Reading your description of the aftermarket ignition system you have and the condition of that dist. cap, would make me wonder if you have a compatibility issue. What is the resistance of the Super Coil you are using?

[NC Rover]

If the rotor spins counter clockwise, don't those burn marks indicate that the timing was too advanced and the spark was firing early?

I believe you are right. If the arm is spinning counter-clockwise, then those burn marks are occurring right before the arm gets to the metal contact point.

So that would mean I need to rotate the dizzy clockwise just a hair. Does this sound correct?