That hurt my head...
It rev's really high when what?
Have you cleaned the OWB?
Mine was leaking everywhere and ran like junk until I tore it apart and cleaned/sealed it. The carb neck, back plate and LSN leaked. I sealed the carb neck and backplate with RTV and I used associated green slime on the LSN. That helped immensely.
If cleaning the OWB with DA and re-oiling it doesn't make it start grabbing again, the I don't think I'd spend the money to fix it. Unless you can get a new starter shaft and OWB cheaply on ebay. IMO, it's a throw away engine. Good to get you going, but not really worth fixing when it starts to fail.