I'm pulling my hair out. I've had my '78 750F for a number of years now. It never ran GREAT, but it got me around on the very few days I decided to chug around, especially to school and back. It always had a slight miss, and I knew the carbs needed a cleaning. Well, finally had the guts to do a complete teardown and clean of the carbs this past spring. When I say complete, I mean COMPLETE -- removed slows/tubes/needles -- everything. I even rigged up a little system to ensure the accel pump was working an squirting fuel through the little brass posts into the venturi.
Well, now it starts up, the revs float around 3000 rpm, and then plummet, and it dies. I can goose the throttle to keep it alive, but it eventually dies. I did a quick spit test on the pipes, 1-4 not nearly as hot as 2-3. So, I swapped the Y/B leads to the coils and swapped the plug leads, effectively switching the coils. Same problem. 1-4 warm. So, it's not the coils/wires. Bike has new plugs too. I then swapped the condensers to rule them out. Same problem. 1-4 timing is good too!
What do I do now? The bike is bone stock as far as the powertrain goes. Thanks in advance forum!