I have a 1981 Catalina 38'. I have owned this boat and sailed it more years than I can count. I love going to Catalina Island on nice summer days but I have a problem. My boat is located in San Diego, and usually the direction to Catalina for me is up wind. That makes for a 13 hour boat ride to get there. The main problem is that when I rev the engine to around 2000 rpm, the whole boat starts to vibrate and make a really load noise. A lot of people have told me this is probably a cavitation issue, however I just don't believe that. This boat has made that racket from day one, and I have a hard time believing that a brand new boat would rattle so much. This problem not only makes the boat ride unpleasant, but causes for a slower ride to control the problem and I assume it is doing damage to the engine and prop shaft as well. Please Help!!!!!
Weird vibration on Catalina Universal Engine at 2000rpm
- Thread starter AMICUS
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An '81 boat... The rubber in the motor mounts has long ago worn out.
You could also have a broken mount, too.
Time to replace 'em. Then put a dial gauge on the shaft and check it.
How long's it been since the cutlass bearing was replaced?
A visit to the boat yard seems to be called for...
(not what you want to hear, but I just spent some coin for a new shaft and alignment for our boat; this got rid of 95% of our vibrations.)
Low percentage chance, but could you have whacked someting with the prop and bent one blade a little bit, recently?
Best of luck,
LB
You could also have a broken mount, too.
Time to replace 'em. Then put a dial gauge on the shaft and check it.
How long's it been since the cutlass bearing was replaced?
A visit to the boat yard seems to be called for...
(not what you want to hear, but I just spent some coin for a new shaft and alignment for our boat; this got rid of 95% of our vibrations.)
Low percentage chance, but could you have whacked someting with the prop and bent one blade a little bit, recently?
Best of luck,
LB
For starters, what engine? Most likely an M25. You may be able to poick up some ideas from our C34 Critical Upgrades page: http://c34.org/bbs/index.php/topic,5078.0.html
There is a ton of M25 engine information in our C34 Tech wiki: http://www.c34.org/wiki/index.php?title=Diesel_Engine
Could be a whole bunch of things. I recommend some detective work at your end, check some of tghe ideas out and get back to us.
Good luck.
There is a ton of M25 engine information in our C34 Tech wiki: http://www.c34.org/wiki/index.php?title=Diesel_Engine
Could be a whole bunch of things. I recommend some detective work at your end, check some of tghe ideas out and get back to us.
Good luck.
When I bought my 1978 32 Oday and went to deliver it to its home port 15 hrs away we noticed at 2000 rpm and higher a horrible knocking noise that sounded like a bearing in the transmission well it was too late to turn back and we motored on and go home without any problems,I figured I'll have to yank the tranny and have it looked at but low and behold after some research I read about shaft alignment and thought about that noise and proceeded to replace all motor mounts cause they looked like hell then pulled the shaft and had that the flange checked and faced then learned how to align the engine to the shaft and all the noise went away
There was a Catalina 36 in our club that has the shaft touching the stern tube on the engine end. As a result, the shaft transmitted the engine noise to the hull and greatly amplified. At the end, the owner was lucky to have discovered it as the shaft tube almost worn through.
The root cause wasn't bad engine mount, just poor alignment, most likely from the factory. The boat had very little use.
Unfortunately, it is very difficult to check in the water. You'll have to pull the boat, remove the shaft log and run a long feeler all the way around the shaft tube and the shaft to make sure not touching.
The root cause wasn't bad engine mount, just poor alignment, most likely from the factory. The boat had very little use.
Unfortunately, it is very difficult to check in the water. You'll have to pull the boat, remove the shaft log and run a long feeler all the way around the shaft tube and the shaft to make sure not touching.
The alignment on my Cal 29 was SO bad the cutlass bearing was worn at a huge angle
The sterntube was badly from the factory it could not be lined up with the strut and motor
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