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pfile 07-16-2013 10:44 AM

Replaced engine mounts now how do I align ?

I've replaced the engine mounts on my Sabre 30 W18 engine and now am faced with aligning the engine.

I'm a little daunted.

Any tips from the experts would be much appreciated, need to get her roughly aligned this weekend so we can get in the water and start the season.

If you want tips on how to change a Sabre 30 W18 engine mounts just shout. Basketballs are involved. Oh try not to break off one of the lag bolts in the engine mounting bed, if you do that like me you will have to cut out and re glass the entire thing... it's been fun :)


arf145 07-17-2013 12:19 AM

Re: Replaced engine mounts now how do I align ?
To play the basic alignment game, first you need a feeler gauge of the appropriate size as stated with your engine. I believe the Yanmar spec is .008 inch, for example. With the output flange disconnected from the shaft flange but pushed together and the engine mounts loose, you check the gap at 12, 3, 6, and 9 o'clock around the mated surfaces. If you have too much space at 12 o'clock, the aft end of the engine needs to drop a tad. Too much space on one side means you have to jostle the engine to close that up.

Simple in concept, but the hard part is that you are frequently trying to push around a several hundred pound weight just a little bit. It can be frustrating.

If you have a drive saver in between the two surfaces it will need to be removed to do this.

rikhall 07-17-2013 11:34 AM

Re: Replaced engine mounts now how do I align ?
We bought two sets of feeler gauges that are 5 1/2 inches long. And then when you do as arf145 above says, use two gauges up and down, adjust / left and right, adjust and just keep going til you are within specs.


jsaronson 07-17-2013 02:35 PM

Re: Replaced engine mounts now how do I align ?
Tom is right on, but remember after the boat is launched you have to do it again. The hull can change shape slightly.

T37Chef 07-17-2013 03:07 PM

Re: Replaced engine mounts now how do I align ?
Using a 2x4 or something similar can help leverage moving the beast around.

You'll want to try and get the mounts as close as you can before installing them (too late now I think), that will save you some time being in uncomfortable positions.

Patience is required probably more than anything, it may take you hours. If you can get a helper to turn nuts on one side of the engine you can't reach that can save a lot of time.

The acceptable gap is usually the based on the diameter of the coupling, so if its a 4" coupling your acceptable gap is up to .004 inch. As mentioned, if you have a drive saver of flexible coupling they will have to be removed, you need to be checking the face of each. BTW, the coupling should be fitted to the shaft by a machine shop. I would do this even if I were using the same shaft & coupling just to be sure, its a $100 or less probably.

I did just what you are doing to my old engine, I replaced the mounts and did the alignment myself. I did okay but made one mistake...I used the shaft tube to get the approximate center for the shaft. It result in uneven wearing of the cutlass, slight but nonetheless. What I learned from the mechanic who did the majority of the install on our new engine, was to hold the shaft and turn it while feeling for resistance in the cutlass bearing, therefore you're aligning it with the cutlass not the shaft tube. I hope I worded that well enough for it to make sense.

My last piece of advice, if you have any doubt, have a mechanic check your could save you easily many times the cost of repairs down the road! Just say'in :)

Good luck, its fun to DIY

pfile 07-18-2013 11:52 AM

Re: Replaced engine mounts now how do I align ?
Great info guys and thanks. I will report back.

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