Yamaha 15hp 4 stroke vibration

[River Explorer]

Having vibration problems out of this 2011 motor. Maybe I don't know Yamaha 4 strokes that well but seems really excessive. I havent had it on the water but i think its enough to make your hand tingle when you take your hand off. Has 119 psi exactly on both cyl. Starts and runs great. Any ideas what's going on? Fist thought is the fly wheel. I dont see it to be off center or bad formation. I know that means mothing on weight. Im thinking about taking the lower unit off to eliminate the shaft. Although the prop is original with no damage it's a starting place. Thanks.

 

[River Explorer]

One thing I did notice was that the spark wasn't huge just about bright enough to barely see.

 

[River Explorer]

Put the correct gap on the plugs and it helped a lot. Still has some vibration though