It sounds like an ignition miss on the #1. Check the wire with an ohm meter to make sure it's good, also sheck the plug itself, make sure the ceramic isn't cracked. Then check the dizzy. Is the rotor and cap in good shape? Are there any visible signs of crossfire or corrosion? If it's not something obvious with the ignition system I'd start looking at the gaskets around the intake, maybe one of the ports isn't completely sealed and you're getting a vacuum leak.
"It's not having what you want, it's wanting what you've got!" - Sheryl Crow