Hey all!
I have had recent issue with a 720 during cold starts, outside of that runs perfectly once warm, and it will always start but not without attempting to crank several times.
Looked at fuel delivery since the pump was exhibiting malfunctioning behavior i.e. got increasingly louder over the last few weeks, and eventually stayed on and ran continuously until power was cut off. I replaced the pump and filter (placed the filter after the pump fram g3 type, adding this for context as I recently got delivery of different filter similar to what was on before that i will install pre-pump).
Now, after i did this, pump behavior went back to normal, carburetor site bowl at half full. But now i started hearing a buzzing sound underneath passenger dash, i removed the plate holding the relays, and by the look of it, its the fuel pump relay buzzing, not all the time, but frequent enough. I cleaned the chassis and block ground terminals, and battery posts at this point. Buzzing went away, but after 24 hrs, its back. Now interestingly, when i pull the choke relay, the fuel pump relay never buzzes, tried a bunch of times, soon as i plug the choke relay it starts buzzing again, same thing when i tested with another choke relay.
During all this, I also noticed that the choke is wide open all the time, even when cold, pressing the pedal does not close the choke plate, curious what would cause this? Furthermore, looks like the blue wire at the back of the choke heater got slightly burned at some point, I tried to pull it but it seems stuck on there and didn't want to break anything.
Long story short, trying to figure out why the choke wont close, and eventually figure out the buzzing issue of the fuel pump relay and/or whether any of the above context provided are related.
Thanks!