I pulled the carb off my 702 this aft and thought I would offer the following hints as your 750 is very similar:
1) My linkage rod had fallen off and diappeared in a black hole. Removing the recoil cover opened up that side of the saw and the rod was easy to recover. Pay very close attention to the orientation of your throttle rod. It will only work 1 way. If yu still have the rubber grommets that are on the choke and throttle rods, be very careful when you remove them to take carb out. The grommets hold the rods in position and prevent the rod ends from falling off the attachments points.
2) The carb will come off the saw with the box. There is a small gasket on both sides of the box. Be careful and dont tear them. Although I believe they can be made, there are very small holes for the impulse.
3) Mine has the Tillotson HS166A carb. I thought I had a kit but I dont. I cleaned the carb up and pulled it apart to inspect the gaskets and diaphrams. They appear old but in ok condition so I reinstalled and put the carb back in the saw.
4) Removing the recoil cover will expose your fuel line from the tank to the saw. It will also give you the chance to clean that side of the cylinder that you cannot reach from the clutch side. Mine was packed with sawdust/oil. The fuel lines appear to be OEM and I decided to test the whole line as I do not know the age. I unplugged the filter in the tank, plugged off the fuel line end that attaches to the carb and pressured it up to 7 psi. It held that pressure for 5 minutes so I decided to leave it alone. You will note that the carb end of the fuel line is "belled" and also serves a seal for the hole where it enters the carb box. This could be a problem if replacing the OEM line with tygon. I dont know if aftermarket preformed line is available...but need to look.
Although I have not been completely thru this saw, I am very impressed with the design and build quality. I think having the air intake on the opposite side of the saw that produces the dust and dirt is a VERY good idea. The manual oiler(in addition to auto) and the external idle adjust screw is very handy and not seen on the best of pro saws on the market today. At 16.5 lbs, its heavy.
I will do a compression test tomorrow and try to fire the saw up. Good luck with your project.
Many thanks to Mark for the service manual. As he said, it is very well written and helps a lot.