SailNet Community banner
  • SailNet is a forum community dedicated to Sailing enthusiasts. Come join the discussion about sailing, modifications, classifieds, troubleshooting, repairs, reviews, maintenance, and more!

Yanmar super vibration

12449 Views 47 Replies 14 Participants Last post by  meanderboy
MY YANMAR 3YM30 IS SHAKING ITSELF TO BITS. It is 9 years old and 3000 hours and has run perfectly until 30 hours ago. The engine runs perfectly in neutral to full RPM. It also runs smoothly in reverse at all speeds. In forward gear, it runs ok until I shift into neutral and try to shift back into forward.

Then the engine starts to shake at 1000rpm and shakes horribly and starts a clacking / grinding noise at anything over 1200 rpm. It is truly frightening

On the advice of the Singapore dealer, I replaced the engine mounts and vibration damper. No improvement at all.

Finding an available mechanic here is very difficult, so any suggestions what to look into would be most appreciated.
1 - 1 of 48 Posts
Does the engine run well out of gear at the full range of rpm's? If so, the problem is either The gear box, alignment, shaft or prop. There are no other possibilities. The gear box is so simple on a yanmar, I'd be very surprised if that was the problem. When you replaced the mounts, did you check for alignment? You do this with a feeler gauge at the coupling? You can adjust the alignment with the motor mount bolts. If you cant bring it in to alignment, you may have a bent shaft. Take a swim and check the prop. Your problem may be frustrating but it can be solved by moving from front to back, eliminating culprits as you go.

Good Luck!
1 - 1 of 48 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.