MSD 6AL Timing problem

[Nuke427]

Okay, so I get my carb all tuned to perfection and now I have timing issues. Total timing set around 35. Car idles fine, but I put the timing light on it and rev it and through mid rpm range, timing gets all out of whack then is restored in the higher rpm range. What the heck? Bad box? I checked all connections and all seem good, even reconnected a couple suspicious ones. Any advice?

[mr0077]

Make sure your timing light is compatible with the MSD...most of the electronic (dialback) lights won't work according to MSD...use a standard light as a backcheck...

[wilf leek]

MSD 6AL outputs multiple sparks up to around 3000 rpm (i.e. 2 or more sparks per firing point). After that, one spark per TDC. (or whatever your timing is).

Could be this is upsetting your timing light. I believe that inductive timing lights are specifically warned about by MSD - could be worth a check on their site/call to their tech line.