MSD 6AL missing

[FatBoy]

I have almost identical symptoms with my engine. I am also running and MSD 6AL and MSD Pro Billet distributor.
At lower revs, it feels fine, but when cruising at around 3,000rpm, it sounds like it is misfiring and will hesitate and pop if asked to accelerate. Once accelerating, it feels fine again until it settles to an even cruise rpm.

Having read this thread, it sounds like I have to ruin a cap by drilling a large hole in it just to check if the phasing is the problem.

Oh well, needs must I suppose.

One more point, the central terminal in the cap is recessed below the level of the steel ring around it. That doesn't seem right to me, but can someone please confirm. Everything is just over 1 year old and has done less than 3,000 miles.

Paul

[Excaliber]

FatBoy, the center black carbon thingy should not be recessed from the metal ring. Your center cap thing is broken, an all to common occurence. I've replaced my cap twice now for that reason and that's really starting to piss me off. MSD needs to get their act together on that issue.

[FatBoy]

Could that be the cause of my misfire?

Given that my cap is already knackered, it guess it doesn't matter that I have to drill a hole in it to check the phasing....unless the broken terminal won't allow me to get reliable results from the phasing test.

Thank you.
Paul

[Eljaro]

If your center button is worn you need a new cap. Use this one now to make the hole in it. Mark the terminal with white paint ant make a vertical white line on the rotor too where the rotor terminal is.
I did bend the rotor center spring upwards to make real pressure on the central button in the cap. Centrifugal force tend to push it away and down.
I got myself the cap with the holes drilled in it to prevent ionization and rust inside the cap.

[FatBoy]

Wow, that's some hole.

The MSD articles suggests drilling into the top of the cap. Is there any special reason why you went into the side?

Paul

[Eljaro]

If you drill a hole on top with all the spark plug cables you see nothing.

On the side you can mark the rotator with white paint where the tip is and you see exactly when the spark jumps.

[FatBoy]

Originally Posted by Excaliber

FatBoy, the center black carbon thingy should not be recessed from the metal ring. Your center cap thing is broken, an all to common occurence. I've replaced my cap twice now for that reason and that's really starting to piss me off. MSD needs to get their act together on that issue.

I've just discovered that the centre terminal is removable. The external terminal post unscrews and the rest taps out, but I can't find a replacement on the MSD website.
What is the point of having it removable if they don't supply replacements?

Paul

[Argess]

As per one of the posts above, I'd be looking at the carbs. Why? Because you say it doesn't misfire under hard acceleration.

Also, I've read that some computer igntion systems do retard the timing at higher rpms. You could be seing that if the hysterisis of the computer retarding is tight and occurs in that 3000 to 3500 range.