It was a combination of both. The original carb is normally used, in our applications, on a 150cc engine, so it was too much carb. The reed blocks were a straight through design with waaaay too much open area around the reeds. All that has been taken care of with the new engines, and those that made the request received new carbs, reed blocks, or both. There was a small fee (postage) for a new plastic reed block, and a larger fee for a replacement aluminum one. There was also a fee if you wanted a wga 9 carb ro replace the wb 25 that they originally had.