Best way to prevent the engine block from vibrating

[Sherry]

I have a friend who has replaced the engine with a new one. The engine has been shaking since. He has replaced the engine mounts and new brackets, but that seems not to work. Given that the engine runs, and vibrations do occur, the person is out of options. During the engine replacement the mounts and brackets were replaced and refrabricated to compensate for any difference, but still the vibration is occuring to the point of concern? Too much vibration will cause friction against other lines and connections, as most sailors are aware of.  Any suggestion?

It does not happen when the vessal is in nuetral. Reverse is worse.

[Sherry]

Propeller is a standard, he did have a feather prop. that why I answered yes before, he got rid of it because it "clunck" when it went into gear. Mainly used for racing anyway, less drag, not by much. I had this conversation like a year ago with him about that. I know a good amount of people with boats, sometimes it's hard to keep them organized! LOLOLOL

[Sherry]

standard meaning a fixed prop. Let me use the correct terminology before you all think Im unaware! LOLOL, then again, I act dumb and play stupid. It's a good thing sometimes! LOLOLOL...only kidding.

[Sherry]

Yanmar 2YM15, diesel!!!!

[zeehag]

sounds like shft misalignment.

[Sherry]

Most likely a shaft misalignment or things just need to tightened here and there. It's new, therefore with running it since the installation, things probrably loosened. I would say your correct. Since the weather went sour this weekend to move the vessel ( she is coming out of the water for yearly bottom work ) we were going to adjust everything while on the way. Holding station if need be. Like my last post. When we fix it, I will keep everyone informed on what the issue was. I do not foresee anything serious, she is a strong vessel.

[cptn_steve]

Just as a side note, don't do any prop shaft alignment while the boat is hauled out.  That must be done in the water as you can have some torque of the hull while on the hard and mess up an alignment.

[Sherry]

Cptn. Steve,

Thank you, but I already know this, that is why I will be holding station. We've already went over the planning on it!  We're all squared away, the only thing that is giving us an issue now is the damn weather. Should of did it early, but I guess one can not have everything!

[Sherry]

Hey Capt.

Did you see my post. We had to shift the shaft, and my friend Hank marked it; this was he knows were her happy medium is. We idled her and cranked her to find and see what the hell was rattling, etc. it was the shaft that just shifted, not much really...but we pushed her back a bit, and tightened a few bolts, screws, etc. marked it off...and she purrs like a kitten now! We will be taken her out of the water this weekend, again checking the shaft for dis-alignment, but I do not see her shifting now. While she is out of the water, bottom job, etc. she will be getting new grundiens put on, etc. Hanks doing preventitive maintanence. This is a good thing! Cannot believe it was just the shaft being dis-aligned by a few inches that made all that ruckess, but he did check the engine mounts, just incase. Vibrations, and pressure that an engine puts out can shift anything. We never assume that it does not have side effects on other machanics...!!!!

[cptn_steve]

Don't quite know what you mean with the shaft shifting.  The only thing that comes to mind is the shaft slipped aft out of the coupling a bit.  Is that what you meant?

[Sherry]

Yes, sorry, I was really tired when I wrote that last night. But yes! It was not that bad. Seemed like a few minutes to fix. My friend was all worried it was something bigger then that, but it was not. It sound great now. He marked it , as to were it is now, so if it shift again, he knows exactly were it's supposed to be. The question is how did it shift? We will check it out again this weekend. He was mainly worried about other machanics being shifted around because of it; houses, mounts, etc. Did not want surprise leaks!

[cptn_steve]

There should be two set screws on the shaft side of the coupling.  These will keep the shaft from moving fore and aft.  They should also be wired together with stainless steel wire to prevent their loosening.

I'm attaching a photo I took of mine.  Although it does not show it well, you can just make out the square head set screw on the lower left.  The other set screw is out of site.  You can also just make out the wire going towards the other set screw.  The shaft should not be movable by hand in the least bit.

 

[Sherry]

Steve,

You went one step ahead of us...my friend is picking up more wire today or tomorrow...he figured that out today! He was missing the wires, he stated it should not move since the readjustment and tightning...but that was funny, same thing stated. We're good! Thanks.