Engine misfiring and stumbling

[mr0077]

When it happened to me the first time it was plug wires. The second time, I changed the plug wires first thing and again it fixed the problem. Also had a problem once with the MSD cap.

[jhv48]

Before you start messing with the advance mechanisms, replace the cap and see if it runs better. That looks like carbon tracks on two of the posts to me also.

If the engine ran fine before the backfiring started, then just find the miss and then it will run fine again. No need to start messing with the advance mechanism unless you want another can of worms loose all over your garage floor.