4 stroker centrifugal clutch help!

I see what you're talking about... that bronze bushing in there is toast. If you know the inside and outside diameter of the bushing you should be able to find a replacement. These are usually pressed in at the factory but if you heat up the housing in an oven and freeze the bushing it should slide right in.
Of course, if you're going to bore it out to fit the bigger output shaft, talk to the machinist, they should be able to put in the right bushing for you when they do the bore job. After that you should be good to go.

Noooo... The reason for the bushing is because the metals have to be dissimilar. If you were to let steel rub against steel (or any similar metal to another similar metal) like that it would eventually heat up and weld it's self together, but even before that could happen it would gall up the crank snout or the clutch drum pretty badly and pretty quickly, especially on a non lubricated or poorly lubricated area like this. The machine shop will be able to bore this out and install a 3/4" bronze bushing for you and then it'll be just fine..
They usually keep different sizes of bar stock and tubing in these type metals just for these purposes. Now if you can find a 1" diameter bronze bushing that's 3/4" inside diameter and close to the same length (longer is better than shorter because they can always cut it to the right size, but they can't add to one that's too short, but if you find one that's like 1/8" too short it'll still work) on ebay or on the net somewhere, they can bore out the hole and install the bushing for you which would save you some money.

Short answer is:
Unless you have some need for this particular clutch, it would probably be cheaper to just buy a new one made specifically to fit your application.
Even repaired, this clutch is nothing special and not worth repairing in my opinion, unless you can make the parts yourself or find them cheap.