Carbs....
You have the BN-48I carbs. They are set up by the pto carb, part number 2750500332 and the mag carb, part number 270500331.
Like timmyboy said, use the springs in your carbs if at all possible.
Why do you think you need a rebuild. A lot of the time, you can remove them, clean the carbs filter. You have to remove the fuel pump cover and the body assembly to get to it. Be careful with the gaskets, you should be fine. Just clean what you have, run it. If it's no better, then buy the new kits.
Good job to timmyboy for his suggestions, I couldn't have said it better. Your quickly becoming a respected member of the forum in helping to trouble shoot. Thank you for your time.