Has anyone encountered engine vibration at certain RPMs? I have a 2005 H33 with a 27 HP Yanmar with approximately 1,200 hours. It has excessive vibration between 2100 and 2900 RPMs. Seems to be getting worse over the years. Does NOT vibrate in reverse or if the transmission is not engaged. Talked to a whack of "experts" and different explanation from each one: cutlass bearing, engine mount, flange, propeller, shaft etc.
Engine Vibration
- Thread starter champers
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It sounds like it could be any of the above.
I assume you will be pulling the boat out of the water for the winter. It is a good time to start checking things out. I would start with the shaft/prop/cutlass to see if there are any issues there.
I assume you will be pulling the boat out of the water for the winter. It is a good time to start checking things out. I would start with the shaft/prop/cutlass to see if there are any issues there.
Yes, definitely have had that on H356 with the same engine. In my considered opinion, it's related to hull flex. Mounts, shaft alignment, etc., etc., all check out, and still there is intermittent heavy vibration at certain revs, in certain conditions. What changes: the hull, only sliightly. Remember that just a fraction of an inch can throw things off. There's also the obvious reason that I've seen some flex when the boat goes on the skid, again, even though everything is checked out first. and Hunter has acknowledged some flex, at least in some early numbers of my model.
Another reason I feel hull flex is to blame is that things got a lot better this year when I installed on of these, a flexible shaft coupling by PYI. http://www.pyiinc.com/index.php?action=shaft-coupling§ion=rd_marine It makes sense that this device would smooth out variable flex-caused problems. Unlike a realignment, which is fixed, this provides some flexibility to handle problems as they come and go. But regardless of the cause, this thing has really smoothed out my reves. It is simple to install, and I highly recommend it.
Another reason I feel hull flex is to blame is that things got a lot better this year when I installed on of these, a flexible shaft coupling by PYI. http://www.pyiinc.com/index.php?action=shaft-coupling§ion=rd_marine It makes sense that this device would smooth out variable flex-caused problems. Unlike a realignment, which is fixed, this provides some flexibility to handle problems as they come and go. But regardless of the cause, this thing has really smoothed out my reves. It is simple to install, and I highly recommend it.
Yes, haul out was last Monday. Agree that now is the time to look after anything that is only doable on the hard. Already did the shaft and prop. Will look into the cutlass.
Thanks Paul. The flexible shaft coupling sounds like a great option. Sounds like a "cure all" for a number of possible causes. We'll know if the spring whehter or not it worked.
I'll second Paul356's comments on the PYI coupler. We put on on our 356 5 years ago and it made a huge improvement. needs about 1 5/8" of room, so your prop will move aft slightly, but no issues with that small a move. probably improved water flow through our cutless bearing by moving the line cutter away from the strut.
Another vote for the coupler. Sound likes its' the way to go. Appreciate the input.
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