Engine Mount Bracket

[Rick]

We have a 1990 Catalina 34 and have been having problems with the L-shaped brackets that join the engine to the front engine mounts (isolators). We've had the boat two years and about two weeks ago noticed that both brackets were broken. The brackets do not appear to be standard for the Universal M25-XP, but may have been a Catalina modication.  In any case, we had new 1/4 inch stainless steel brackets fabricated.  Now, less than two weeks later, one of the new brackets has broken.   Has anyone heard of similar problems? Rick

[Mike and Joanne Stimmler]

Rick, are you noticing a lot of vibration from your engine. I  so you should have your prop shaft allignment checked. heavy vibration could be stressing the mounts.   
Mike

[Jim Price]

Rick, you might want to validate the vibration in all three positions, forward, reverse, and neutral.  If it is shaft or prop, you should have vibration in same RPM range in both forward and reverse but not in neutral.

I have a 91 with XP25 and have a vibration in range of 2000 to 2400.  My mechanic tested and vibration is same spot in gear or out of gear, meaning mounts are not absorbing enough vibration at this point.  He showed me how the mounts have "flatten and got fatter"a little over the years plus when original, they were pretty hard rubber to start with.  Just transmits vibration to stringers.

I am planning a mount replacement later this year when it is more convenient.  The old three-banger is going to vibrate no matter what you do, but you can manage the amount you feel - plus help keep shaft in alignment.  AND Stop Breaking Those Brackets!!!!

[Ron Hill]

Rick : As I told your wife on the telephone, I've never heard of one of those engine mount bracket breaking.  She mentioned that one of the old brackets was welded.  I'll guess that there was a freak failure of that bracket and I'll further speculate that who ever welded it may have forgotten to "stop drill" the crack so it wouldn't migrate any further.  I'll guess that that weld failed and then the weight/vibration of the engine on the remaining 3 caused the other front bracket to break.

Anyway, I suggested that you're in Mystic Conn. now and you should call Hansen Marine who is a Universal dealer and order 2 new forward engine mount brackets.  I also mentioned that you should change out the original engine mounts while you're at it.  I'm not on the boat, but I'd say that the Universal engine mount bracket is thicker that 1/4" and you surely don't need stainless. 

If you have new mounts and clean injectors your 3 cylinder will run just as smooth as a 4 cylinder thru the entire RPM range.  I've had Marina owners ask me if I wasn't going to start my engine before I wanted the lines cast off - the engine was running!!

Hope this helps.  Keep me posted on the outcome.   

[Rick]

Ron,  We are at the Brewer yard in Mystic. The mechanic  found that the engine was seriously out of alignment.  After adjusting the alignment in the water, the mechanic told us that there was a lot of vibration in the shaft which to him means a bent shaft. We are planning to pull the boat to check the shaft, but don't feel confident we have identified the problem.  Does this seem right to you?    How can we tell whether the vibration is from a still existing alignment problem or whether it is the shaft?

We really need to learn more about the boat and appreciate all your help. Rick

[Ron Hill]

Rick : A bent shaft and engine misalignment together could put up one hell of a vibration. 
I'd suspect that that vibration could put excess wear on the engine mounts, but don't think it would break a engine mount bracket.  If the mechanic aligned the engine in the water(the only way you can correctly do it) and suspects the shaft - here's my best guess:
The mechanic isn't able to get the engine properly aligned.  The cause could well be a bent shaft - it doesn't take too much of a bend either.  When you pull the shaft it's easy to tell if it's bent - like rolling a pool Que on a pool table.

With all that being done, I'd change out the engine mounts, cutless bearing and install a new stainless shaft.  If the $$ still hold out I'd realign the engine (in the water at least 24 hrs after it's been splashed) and add a flexible coupling.  YOU can always add that coupling later.  Also make sure that the new shaft is centered in the packing gland "hole" in the hull.

I'm not too sure about the locally fabricated engine mount brackets, as the Universal brackets have been properly bent during manufacture.  Keep the Faith, after all it's only money!! 
Hope this helps.