Hitting a wall at 4K

Got it fixed. After dropping the tank, pulling the sender, finding that the filter sock was cracked and no replacements could be found. I put the sender back without it and I monkeyed up a filter just to the outside of the tank. That didn't fix it. So I disconnected the tach, didn't fix it. As I was reconnecting the signal wire to the tach I looked across the engine bay and saw the ignition module. It looked fine but I decided to swap it with one of my spares. Bingo, pulls like a raped ape till I can't bear to look at the tach anymore. Wish I had thought of that before I got covered in 40 years worth of grime and dirt.