mk-bn38/44 spr
That's the rebuild kit part number. Do not use the springs, use your old ones. You also need new needle and seats with a viton tip. I think you need 1.2 for the 720's. Make sure you get genuine mikuni kits. Do not use aftermarket kits or needles and seats.
If you're careful, you can disconnect the throttle linkage and probably not have to adjust your idle. There are 2 screws that hold it onto the MAG (front) carb. Remove those and carefully remove the cables. Yes, it's tough but it's less set up on the back side of the project. Hopefully the mounting screws come out easily, if not it's gonna suck.
I remove the engine cover to work on it. Then you can kinda lay on the swim deck. Open the engine cover, wedge a towel in the gap under the cover, I think yours has a grab handle? If so slide the towel to the center, make sure it's tight, it will give you support. Then, locate the hinges. Some guys say they remove the pins from the hinge, mine are not removable. Take a pencil, trace around the hinge on the boat side. Remove the outer 2 screws on both hinges, use plenty of WD-40 while removing the screws, you can't use to much, you don't want to break one. Then on the lift struts there is a clip at the end, it's what holds the end from popping of the ball stud. Take a little screw driver and pop that clip out a little bit, not all the way off. With a helper holding that side, repeat the process, then finally remove the last 2 screws in the hinges. Then remove the engine cover. I'ma bigger guy, I can do this solo, non sk boat, I think your cover might be different?. This is the only way to do this job on my opinion. I refuse to hang upside down.