yamaha 50hp sluggish

Question
Thank you in advance for your time.  I have a 50 hp Yamaha 4 stroke that is verry sluggish on the way up to get up on a plane.  When it is up on a plane it runs about 4000 rpms when it usually runs about 5500 rpms full throttle.  I have a 16 foot key west cc, and I try to do as much work on it as possible when it is easy enough.  Also the enginge shakes terribly and I recently had a new prop installed.  What are some of the basics I should look for before taking it in to the shop?

Answer
Hi Todd...Thank you for selecting the undersigned to reply to your question. By the way, I'm not a mechanic.

The primary symptom appears to be excessive engine vibration, which suggests a number of possible promblems. First, has a thorough and recent engine analysis, compression test, and tune-up been undertaken? When the new prop was installed, was the prop shaft checked for damage and alignment? Have you experienced lower unit oil leakage? Have you experienced overheating of the engine periodically or consistently? Have you throughly checked the transom mounting bolts for proper securement?

In the long run, it may be far more economical to consult a local marine mechanic/technician who is qualified and reliable to diagnose the symptoms and resolve whatever issues are discovered.

Safe Boating
Ron