Originally Posted by bblueser
my neighbor drains the old oil for about 5 minutes, then adds 15 oz of new oil. He says the dipstick shows full.
I mention this because I wonder if his engine problems were caused by overfilling the oil?
How sensitive is the GCV190 to overfilling with oil,
Your neighbor's technique sounds spot-on. Draining warm oil for 5 minutes will likely get all but a few tablespoons worth out of the oil pan.
Overfilling the oil may cause the oil to drain through the breather tube and soak the air filter. This can cause the air supply to be reduced, resulting in a rich-running engine.
Not aware of any particular sensitivities in filling the GCV190's engine oil.
Caveat: I work for Honda, but the preceding is my opinion alone.