I have a 1997 motor that just had a new powerhead, new coil, and rebuilt carberators put on. The oil injector was taken out. I just ran it for a test drive (after mixing the oil and gas). It ran fine for about 15 minutes and then it dropped power from 4800rpms - 4400rpms. Severe loss in torque - took close to a minute to plane - ran like it was missing. Does anyone have any ideas of what can be wrong now???