Y-30 vibrations

[palacegrand]

Hi Folks,So I bought the Y-30 (Yeay!) and brought it back to Victoria this past weekend.I get a LOT of vibration & associated noise while motoring.Questions: - Is this just the way it is with the YSM 12 and the long shaft from the V-berth?- There's the possibility of an imbalanced propellor I suppose; folding 2-blade- Motor mounts? And has anyone tried different ones?- Anyone tried an elastomer coupling?ThanksCraig

 

[Bob15082]

Not normal

Greetings,It's not normal for the engine or shaft to vibrate. On my 30, if you closed the companionway hatch, you could barely tell that the engine was running while under way, except for exhaust drooling.If the boat has a folding prop, that would be the prime suspect, also in the lineup would be a worn out cutlass bearing.Regards,Bob

 

[Bryan]

seen it

hat is the name of your boat? We chartered a a Y30 out of Lund BC years ago, that had a substantial vibration. The boat was called Distant Drum.

 

[palacegrand]

Actually the cause .....

Hey Bryan,Don't think that's my boat. Her name when I bought her was "Amadeus". There are some equipment manuals on board with "Eclipse" or something similar on, so that may have been it's original name. For anyone that may be interested, the cause is likely the steady bearing/pillow block at the head of the shaft. I had my mechanic out to check it all over a couple of weeks ago. The YSM 12 in good shape but we noticed a fair bit of slop in the steady bearing. Also at some point a dripless shaft seal had been installed which doesn't offer any of the support of the old shaft packing setup where the shaft exits the bilges. Mechanic points out that there should be no more than 4' of unsupported shaft.So, hope to haulout two weeks from now, replace the one bearing and install another nearer to the stern.At that point I'll also get a chance to check out the cutlass and shaft support and prop. Possible that they're contributing some too.B. O. A. T.Still loving the boat though!cheers,jcm

 

[Luke Schouten]

All the little big stuff

Craig, some of my thoughts, It is a good possibility that the unsupported run from the bearing to the strut bearing as a next support is the reason of the vibration. This is my best guess.It may also be caused by the points you are making yourself.Personally, I have an elastomer bearing and in addition a rubber tire break at the bearing, which absorbes any vibration.Your bearings may have to be replaced. It is an easy test to find out if this is needed.Play in the bearing or mis alignment is checked with a gauge. My YSM-12 is original and has not been exposed to electrical charges on their way to the salt water. When I bought my Yamaha I installed 3 bus plates, front mid-ship and back. I ran a tinted wire from the front to the back of the boat connecting the bus plates and in the harbor a sacrificing sink plate hangs overboard. Every item which is in connection with salt-water and the flow of electrical charges from power sources is connected to the bus plates and therefore bonded. The engine was also bonded to this system and is not used as a sacrificing anode for all electrical grounded and "deterioration" of metal. This is very important! I will make clear here that your YSM 12 may be used for a life time provided it is treated properly and not abused by a poor electrical system. Oil and diesel which mainly causes the deterioration of motor mounts is also a reason of vibration. If your engine is running does it show movement or is the vibration mainly in the shaft?The shaft bearings are of the "open" type (I don't know why?) and need greasealmost every other day. I use the heavy marine grease, which will stay on the bearing for a little while longer. The lite greases are useless and will spin off faster than is practical.The strut bearing may have some play in it. 1/16" is OK.The propeller may have to be calibrated for its weigh or pitch it may be thereason of your problem. I hope this info will be to some use. Luke Schouten

 

[Bob15082]

dripless seals--NOT

Greetings,One of the guys in the cruising club had the bellows on his dripless shaft seal fail, and his boat started to sink. Fortunately, he was on it at the time, and was able to find and correct the problem before it converted itself into a submarine. If your seal has this possible failure mode, beware.Regards,Bob

 

[palacegrand]

Now picking up "Good Vibrations" .....

Well folks,Hauled out two weeks ago, and had one of those rare moments I thought I'd never see .... my Y-30 coming out, and there on the hard was another y-30 that went back in about 3 hours later! (Brian & ... Linda?, boat named "Indecision")Anyway, during the haulout, I stripped the VC Offshore, stripped and recovered the keel with "Blue Steel" and then recovered all with Micron CSC. There had been some amazing growth primarily on the steel part of the keel (like about half or the Vancouver aquarium) so I tried my best to give it a proper sealing. I just had a chance to overnight Sat/Sun and can tell you that she goes a tad quicker now!BUT ..... The best part was during the haulout having the steady bearing close to the engine replaced and adding another steady bearing close to the dripless seal so that the shaft is now well supported. (Thank you Keith from Gartside Marine!) What a difference to the noise level and vibrations! Still like to find the sweet spots in terms of rpm but now can listen to the radio while motoring, which was virtually impossible before. Even with the companionway open, at the right rpm the loudest thing was the exhaust sputtering.Now if only this darn work thing didn't get in the way of my sailing time!cheers all,Craig