shaft packings and engine alignment

[bloboater]

hey i recently bought a sailboat that has been sitting for years. Diesel runs fine (ysm8) but stuffing box leaks too much while in gear and i get too much vibration at higher rpms..in gear. Was gonna replace shaft packings and align motor.....just looking for any first timer hints that would help. Cutlass bearing is in great shape
thanks

 

[jerryat]

I would replace the gland you have with a Volvo shaft seal (see very recent posts) which should eliminate the leaks unless the shaft is badly scored/grooved.

The amount of movement these can accomodate without leaking a drop is remarkable. Re the engine vibration, all single-cylinders vibrate considerably especially at tick-over, but your problem at higher revs sounds as if either the shaft is bent or the engine mounts are shot.

I'd check the mounts first as there may have been some deterioration during the years of 'sitting'.

 

[bendyone]

Could be the engine mounts, they might look OK but the rubber may have come away from the metal - you cant tell until you lift the engine.
I was a PSS seal which works well.

 

[LittleShip]

All good advice so far, but it could be prop out of balance as well, or even weed growth on it.

Was the boat left in the water for the laid up period.

Tom

 

[wotayottie]

excess vibration can cause leakage at the stern gland, and of course there can be a number of causes of vibration. If the boat is new to you, then at the risk of making the job a bit longer than it needs be, the best thing to do is to start from scratch. in your place I would fist check all the engine mounts for delamination and sag, then check that the engine is standing equally on all 4. at this point split the coupling and align the engine using feeler guages / slip guages in the gap between gearbox flange and shaft flange.

one quick check to see if the engine is out of alignment is to have the boat under sail with the engine not running but in gear and the shaft revolving. if the engine still moves about on its mountings then an alignment job is needed, because you have eliminated the effects of combustion pulses

if the alignment is good but there is still vibration and leakage, then its time to take out of the water. personally I would replace the shaft seal if it is a stuffing box with a modern lip seal type. you would also need to check shaft staightness which is the next most likelty cause of vibration after alignment.

 

[Kawasaki]

If the engine mountings were shot , I would expect more vibes at tickover than at speed, especially with a single cylinder.
I think I would try adjusting the Gland first.
If still no good check alignment as per wotayottie and re pack.
I have re packed on the water numerous times, it can be done.
If still no joy, then I,m afraid it might mean a thorough check of mountings, shaft, stern tube and prop.
Does the engine rev up smoothly in nuetral?