I have just purchased my first sailboat ever and a 1981 hunter 30. I have a vibration in foreward gear only that is sometimes very severe. I know that the prop is out of true by 1/16th of an inch per the survey could this be the sole cause. Has anyone encountered this.The engine a Yanmar 2QM15 is smooth in neutrual and reverse thru the entire rpm range and the vibration starts in foreward gear at around 1000 rpm i do not have tack but that should be a close.
Vibration
- Thread starter Mark Guthaus
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Unfortunately this is probably something that has to be resolved out of the water. Especially since you write that the 2QM is smooth in neutral. Look for a loose shaft in the cutlass bearing and/or a loose strut where it bolts to the hull. An out of balance prop could also be the problem. My boat's original engine was a 2QM20 and it had a small vibration but just around one small rpm range.
I had a severe vibration with my QM20. I had the engine realigned(one motor mount replaced), a new shaft and cutlass bearing with some improvement. I recently exchanged the two blade prop with a campbell 3 blade. Much better. However, I believe that the older two cylinder yanmars just are rough running.
Check the motor mounts, it they are sticky or mushy on top they need to be replaced. You can do one but it's best to to in pairs (front/back).
Check that you have not growth or lines wrapped on your prop.
Check that there are no dings or chips in the prop
Check the alignment. There are a lot of posts on the net no how to do this. It painstaking but not that hard.
Check that you have not growth or lines wrapped on your prop.
Check that there are no dings or chips in the prop
Check the alignment. There are a lot of posts on the net no how to do this. It painstaking but not that hard.
If it is a folding propeller it may be near end of life. I experienced the same issue with my 1987 Hunter 31 3-bladed folding propeller. The vibration would go away once the propeller got into position. But I had to run it in reverse several time before it did. Once I replaced it with a 3-bladed (2-bladed would also work) fixed propeller vibration issue went away. I considered this to be a safety issue.
Thank you everyone for your input i will check things out this weekend and see if i can resolve the the problem
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