My advice is to look for a shop that specializes in Mopes and preferably runs one. If the head guy has a Goodwrench or Roush racing hat on it's not a good sign, but there are some exceptions. Displaying the ability to distiguish good machine work from slop shop crap also helps when you talk to them. They will be less likely to cut corners if they know you'll be checking all their work. I.E. - Specify clearly what you want done. Pistons fitted at .006", valve seats not sunk into the ports, etc. If they look at all confused or irritated by your requests turn around and walk out!