Help with Yanmar44 vibration

A

ADuke

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Apr 30, 2013
9
Hunter Legend Bristol
I am sure someone can help me. I have a 40' HunterLegend with a 44hp Yanmar engine.
I have tried tightening the mounts, realigning the shaft but still getting very bad vibration at 2100RPM's. Can only get 4kts at 2100 then it feels like the boat will rattle apart! I've read in the forum about engine mounts and different props. Any suggestions on what/ how to check before spending money on something IDon't need? Currently have the factory 2 blade prop.
Thanks to all!
 
O

odaydokay

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Jul 5, 2011
747
Oday 28 Madison, CT
How is the cutlass bearing looking? Any play there? Maybe take a quick swim and give the shaft a shake to and fro and see if there is play. A little more background would help others to pitch in. How long was the thing fine, when did it start not being fine. Come on gradually or all at once. Start this season after launching or just yesterday? More info = more responses = more ideas.
 
Roland5048

Roland5048

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May 12, 2004
1,505
Hunter Cherubini 30 New Port Richey
Let's start with the obvious. Are the prop and shaft clean? Is the cutlass bearing worn? Now, although you have tightened the mounts, they may still be worn and need replacing. If all of this is good, we need to start hearing from others with more experience.

Edit: odaydokay got there first
 
kito

kito

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Sep 13, 2012
2,011
1979 Hunter Cherubini 30 Clemmons
Ditto what odaydokay said plus does it happen only in gear or at idle too? Does the vibration come with a noise or just shakes bad at 2100 rpm? Does it smooth out over 2100 rpm?
 
A

ADuke

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Apr 30, 2013
9
Hunter Legend Bristol
Thanks. The shaft and prop have a few barnicles, but not too bad....i think. I tried moving the shaft and it does not move...at least while quickly trying with boat in the water. This issue started after launch this year. After realigning it got better but i used to be able to get 5-5 1/2kts at 2100RPM. Now can only get 3 1/2 to 4 at best.
Also tried changing the fuel filters thinking i was starving the engine.
 
A

ADuke

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Apr 30, 2013
9
Hunter Legend Bristol
Forgot to answer... Out of gear is fine. Vibration is only when in gear.
 
kito

kito

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Sep 13, 2012
2,011
1979 Hunter Cherubini 30 Clemmons
Did you get the barnacles off the prop? What's your bottom look like?..........barnacles too?
 
A

ADuke

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Apr 30, 2013
9
Hunter Legend Bristol
I did not scrape the barnicles off the prop or shaft. Just a quick look. I also did see more on the keel.
I can borrow scuba gear if it should all be cleaned
 
Roland5048

Roland5048

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May 12, 2004
1,505
Hunter Cherubini 30 New Port Richey
Can you get the RPMs to max while motoring? A fouled prop will usually not allow you to get to full RPM, might smoke a bit more than usual, will slow you down, as will a fouled bottom, and cause vibration. The first thing to do is get the running gear and bottom clean. We can go from there.
 
A

ADuke

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Apr 30, 2013
9
Hunter Legend Bristol
Sounds great. Will plan to clean this weekend and reply
Thanks to all the replies to date.
 
O

odaydokay

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Jul 5, 2011
747
Oday 28 Madison, CT
Are you saying with the engine in neutral you cannot easily turn the shaft up near the tranny? Did anyone adjust the stuffing box this season? It should turn freely when in neutral, that is certain.
 
kito

kito

.
Sep 13, 2012
2,011
1979 Hunter Cherubini 30 Clemmons
I think he meant that it didn't move sideways within the cutlass bearing......not rotational
 
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A

ADuke

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Apr 30, 2013
9
Hunter Legend Bristol
That is correct. The shaft rotates freely in neutral.
May have discovered the problem. Today, after releasing from the mooring, discovered i have no forward gear. Only reverse. Tried shifing from down below and tranny seems to be stuck in reverse!
The wife did a great job snagging a mooring so we didn't drift into another boat.
 
Caspurr

Caspurr

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Oct 5, 2015
80
Hunter 33 33 Halifax
I have a 2007 Hunter 33. When passing ~2300 RPM I get a fair amount of vibration which rattles the instruments on the binnacle. It is my first year with the boat so I was basically running it in the 2200 range at around 4.5 to 5 knots depending on wind and water. Most of the time basically for 10 to 15 minutes to get to where I pop the sails. I suspect build up on the prop but not sure at this point. She runs smooth at 2200 and in no rush to pull boat to investigate. Is this vibration normal as you approach 2500 RPM plus or is this something I need to investigate.
Thanks,
 
NYSail

NYSail

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Jan 6, 2006
3,145
Beneteau 423 Mt. Sinai, NY
Dive and check your prop, maybe cutlas, maybe strut. First while running look at engine and see if a mount has broke. T is not normal and better to check now before something really breaks
 
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