Took my buddies new 210 Sanger out yeasteday and it has a bad Vibration. The prop looks good. I'm thinking the Strut or shaft. Has anybody herd of this problem before?
Even though the prop may look good, it still may be out of balance. Take the prop to your local prop shop or boat dealer. They will balance it. If that does not take the vibration away, then check the shaft and strut.
Does he have an extra prop, if not he should get one. Most vibration issues can be blamed on the prop. Even a perfectly balanced prop can cause vibration if it's cups are not matched.
If its new, take it to the dealer and let him do it under warranty. Let the experts decide whats wrong before you waste your time by pulling off the prop.