Desperately in need of a solution for a vibration-ratlling-thumping when motoring at certain RPM on my CAL 2-25 with Yanmar YSM-8hp. I first thought problem stemming from cutlass bearing, prop shaft or even engine mounts. Changed cutlass bearing, corrected shaft, replaced engine mounts. Problem now nailed down to what seems to be vibration between rudder shaft and rudder tube. Tried inserted Mylar sheets between post and tube which did not work (the sheets were swept away). Anyone with similar experience and solution!!!
Cal 2-25 vibration when motoring
- Thread starter leclaira@videotron.ca
- Start date
I'm not sure but it could be the engine / prop shaft misalignment. You might try installing a flexible shaft coupling between the engine's transmission drive flange & the prop shaft. It absorbs vibration & compensates for engine to shaft misalignment.
I use one on my Cal 2-25 & have no problems.
Check out products such as Uniflex 13 (or equal) by Vetus seen here http://www.vetus.com/stern-gear-sys...uniflex-13-shaft-25-mm-incl-4-connection.html
Best,
Ima
I use one on my Cal 2-25 & have no problems.
Check out products such as Uniflex 13 (or equal) by Vetus seen here http://www.vetus.com/stern-gear-sys...uniflex-13-shaft-25-mm-incl-4-connection.html
Best,
Ima
a mis-alignment would not make a thumping vibration, so initially I would rule that out and look for something else...
it could be a bent shaft, or a bent or otherwise damaged prop... not likely to be from the tranny unless you have a noise coming from it.
I would suspect a bent prop blade, or possibly a line wrapped around it.... if the prop had enough wobble due to being bent, a blade missing or line wrapped around one of the blades just right, would cause a thumping vibration, and the warble effect of the water against the rudder would account for it to be showing signs of vibration also... but so would a bent shaft cause this
but a damaged prop is somewhat better than a bent shaft
it could be a bent shaft, or a bent or otherwise damaged prop... not likely to be from the tranny unless you have a noise coming from it.
I would suspect a bent prop blade, or possibly a line wrapped around it.... if the prop had enough wobble due to being bent, a blade missing or line wrapped around one of the blades just right, would cause a thumping vibration, and the warble effect of the water against the rudder would account for it to be showing signs of vibration also... but so would a bent shaft cause this
but a damaged prop is somewhat better than a bent shaft