I had an ASP 1.8 4S and the first thing it did was leak fuel around the HS needle valve seat. I purchased a new needle valve and that solved the leak problem. The engine contiually loaded up at idle so I changed the plug from an OSF to another 4S plug with a hihger heat range. Problem persisted so I sold the engine. I let the buyer no about the problems. Moral of the story is these engines IMO are only suited as paper weights. The old sayin is "you get what you pay for" and the ASP engine fits the phrase perfectly. If you want a reliable 4S engine than buy either OS or Saito. My mistake.