Hmmm. Interesting but I have to tell you I have had regular flexible mounts and a Drive Saver flexible coupling on my boat for 15 years with no problems. Others may wish to comment.
Rich > On Dec 11, 2013, at 18:47, Don Newman <donrnew...@gmail.com> wrote: > > Good post Rick, but one quibble. > If an engine has flexible mounts then it must have a solid not flexible > coupling and vice versa. > > I made that mistake when I repose red my last boat and the coupling destroyed > itself with extreme prejudice in a couple of hours of running. Everything > was aligned but the two components worked against each other. > > I learned later that this is an inflexible rule ;-) sorry I can't provide a > reference but my painful experience bears it out. The original had a solid > mount and flexible coupling and the new engine had flexible mounts so I used > the very substantial coupling. > > > Don Newman > C&C 44 > > >> On Dec 11, 2013, at 14:45, Rich Knowles <r...@sailpower.ca> wrote: >> >> Josh: >> >> I just had a look at mounts on the PYI site: >> http://www.pyiinc.com/index.php?section=rd_marine&action=engine-mounts&sn=1 >> >> Their widget allows you to insert the dimensions of your existing mounts so >> you can receive new mounts that should simply replace the existing units >> with no drilling or other fiddling. I trust you completed that exercise and >> have received the correct units. Note, they are not stainless but zinc >> plated. >> >> Many of our boats came with some sort of metal members in the engine >> mounting system and I suggest leaving well enough alone unless you have good >> reason to make changes. If you do one mount at a time, you should be able to >> simply undo the bolts, back off the positioning nuts, remove and replace the >> old mount and, after all have been replaced, adjust the mounts to position >> the engine correctly. >> >> Well before you start, I suggest soaking the mounting bolts and nuts and >> your propeller shaft flange connecting nuts and bolts with one of the proven >> rust busters previously discussed on this forum. >> >> Also, before you undo the existing mounts or make any changes to the >> adjustment nut positions, I suggest you measure and record the distance >> between the underside of each engine mounting bracket to the top of the bed >> under it and use that measurement to set the top of the bottom nut of each >> of the new mounts. Even if an old mount has settled, it will give you a >> reasonable starting point to start aligning the engine. >> >> Aligning the engine after installing the new mounts will be another chore. >> This involves undoing the bolts connecting the propeller shaft flange to the >> engine shaft flange and fiddling with the nuts on the mounts until the shaft >> is centred in the shaft tunnel, the flanges are concentric and the engine is >> aligned so the clearance between the flanges is equal or within .001 - .002" >> all around. This can be a tricky job and will test your patience, but needs >> to be done as best as possible. After this is done, the system should be >> reasonably vibration free. Ideally the final alignment should be done after >> the engine has settled on the new mounts for a few days and the boat is in >> the water. >> >> To reduce alignment and vibration problems further, I highly recommend >> installing a flexible shaft coupling which will absorb most of the remaining >> shaft coupling misalignment which is inevitable, especially when the system >> transitions from a static state to an operating, loaded condition. >> >> See: http://www.pyiinc.com/index.php?section=rd_marine&action=shaft-coupling >> >> Google will reveal many discussions of shaft alignment on the web. One of >> the simplest illustrations is: http://www.ebasicpower.com/faq/alignib.htm >> >> I also suggest checking your cutless bearing while you are fiddling with the >> drive train. Note the spelling, it's not a sword:) >> >> Good luck. >> >> Rich Knowles >> INDIGO LF38 >> Halifax, NS. >> >> >> >> >> >> On Dec 11, 2013, at 7:33 AM, Josh Muckley <muckl...@gmail.com> wrote: >> >> Hey Folks, >> >> I'm in the process of replacing my engine mounts on Sea Hawk, equipped with >> the original Yanmar 3HM35F. I purchased mounts from PYI. They look to be >> quite high quality mounts and appear to be made of SS. Unlike OEMs, they >> are positively captured so your engine won't go flying lose if the rubber >> separates. >> >> The previous mounts were not OEM either. In fact it appears that the PO may >> have over loaded them or installed used mounts because the forward pair >> appeared very compressed, almost a 1/2 in shorter and kind of inverted on >> themselves. At first glance I thought they were different designs from the >> aft pair. Because they were short it looks like the PO had to build up the >> forward foundations with some 5/8 or 1/2 inch starboard (polyethylene) >> blocks. >> >> Sitting between the engine mounts and the glassed in foundation of the boat >> there are 1/2 inch thick aluminum plates. They run the full length and >> width of each port and starboard foundation rail. Because of the clearly >> redesigned nature of the situation I began to question if these aluminum >> plates should be there or if they too were part of the PO's engineering. >> >> I'm looking for thoughts and advice regarding the engine mount replacement >> task as well as the appropriateness of the aluminum plates. It would also >> be helpful if anyone has torques specs or design details of the fiberglass >> foundation. >> >> Thanks, >> >> Josh Muckley >> S/V Sea Hawk >> 1989 C&C 37+ >> Yanmar 3HM35F >> Solomons, MD >> >> _______________________________________________ >> This List is provided by the C&C Photo Album >> http://www.cncphotoalbum.com >> CnC-List@cnc-list.com >> >> _______________________________________________ >> This List is provided by the C&C Photo Album >> http://www.cncphotoalbum.com >> CnC-List@cnc-list.com > _______________________________________________ > This List is provided by the C&C Photo Album > http://www.cncphotoalbum.com > CnC-List@cnc-list.com
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