Engine alignment - DIY?

[Wansworth]

Lined up my Stuart Turner it had fixed feet and the shaft came thru a fixed stern tube Bering,how I did it I don’t recall nowbutIf I could do it it cannot be at all difficult. Shims where essential but it was back in1976……

 

[Praxinoscope]

I replaced a Stuart Turner engine with a Beta 10 on my previous boat, I did all the work myself including changing the bearers to fit, new prop shaft, new cutlass bearing, replacement packing in the stuffing box, new exhaust system electrics and lining up the engine. I used dial and feeler gauges to get the alignment correct, it did take me almost two days to get it right, but 18 years later when I sold the boat, the alignment was still within tolerance with no vibration under way.
As long as there is ‘good’ access and you don’t mind scraped knuckles and back-ache it’s perfectly straight forward to DIY, if access is poor and you really suffer with back-ache, then get someone else to do it.

 

[Tranona]

If the shaft is fixed in the tube by having an inboard bearing like a Stuart Turner stern tube alignment is very straightforward. With a fixed mount ST the adjustment for height is with lead shims under the feet and if the beds are put in correctly adjustment up and down fore and aft is all that is necessary. Slightly more complicated with flexible mounts as you have potentially more things to adjust.

The problems arise more with stern tubes that do not have inboard bearings as the shaft is not then a fixed point, hence the need for centring the shaft in the tube before mating the 2 faces of the coupling. This can be a real challenge in confined spaces and you then have to dismantle at least the seal to remove the packing or top hat used to centre. When I first replaced my ST with a Yanmar we removed the inboard white metal bearing as a non greased seal was used but there was insufficient clearance for the shaft and it could knock against the side even when it was centred for alignment. Next stage was to fit a piece of cutless into the inboard end and replace the R&D with a Vetus Bullflex coupling which solved all the problems. Later replaced the Yanmar with a Nanni 14 and after raising the beds to suit the new height of the feet it slid straight down onto the shaft.
I have used the same set up on the new Beta installation in my Golden Hind.

 

[jwfrary]

Or get a Halyard Marine Aquadrive?

People sometimes have to ask if our engine is on as one of those with some decent sound insulation makes our engine extremely quiet.

The aqua drive still has to be aligned to the shaft though its smaller, it doesn't remove the problem entirely!

Also you have to make sure the aqua drive is slightly mis aligned to the engine which needs to fall within a tolarance so it's still a minefield!

 

[doug748]

We’ve got a Halyard Aquadrive so lining up the new engine to the shaft isn’t quite as critical as it would be in some circumstances...

Yes. I have a Centaflex coupling which is an expensive option but makes alignment much easier. Not much help for the above but worth considering if anyone is thinking about fitting a new engine