There is not that much compression.

Just stop the shaft moving forward and the disc moving from the face.

Hi Sam,
To get around your problem with the pss, I have loosened the rotor and slid the prop shaft aft to get clearance between the gearbox and the coupling, then retightend the rotor and then put a brace between the rotor and a bilge stringer to stop the shaft moving forward and decompressing the bellows . Be sure to lash the brace in such a way it can't be knocked out.
Last time I totally removed a pss on a boat in the water, it wasn't on my boat so I clamped a couple of pieces of hose together that matched the stern tube and the shaft, then they could be clamped up to totally seal, Doing that gave me peace of mind that the boat would be watertight whilst waiting for the engine.
If you feel like going for a swim you could also hold compression on the seal by clamping a shaft anode up against the cutless bearing to stop the shaft moving forward

is the height of the coupling much different to the existing Sam ?

SandS said..
is the height of the coupling much different to the existing Sam ?

Until the new engine's in place Sands I won't know what the differences are, but, there is a huge height adjustment
on the Betas mountings so matching it shouldn't be a problem.

Ramona, if you read this. Would you use mono 30 grade engine oil in the new motor or go for 15/30 grade ??
And what would the gearbox oil be ??.

Hi sam, my Beta 25 uses 25w 40 standard engine oil, synthetic is not recomended. The gearbox takes one cup of automatic transmission fluid. If you google Beta engine and go to the uk website all the info will be there for you.i like the pump on the side to empty the engine oil, it literaly takes 10 mins to change oil and Filter,no excuses now

I have owned a Nanni and played with a couple of Betas and I see that Beta have done a far better job marinizing Kubotas than Nanni ever did.

As for Kubota engines; there has to be more Kubotas revving their tits off powering mobile lighting plants, generators, welders and compressors etc, around the world than any other brand of engine.

Excellent choice Sam. I am sure that engine will outlast you, me and the next six owners of the boat.

Oils ain't oils as they use to say.
Only ever Castrol mono 30 for me!

samsturdy said..
I've been using mono 30 in the Bukh, I was told it was hard to get these days but I've bought it from Repco in
living memory so hopefully I still can. The reason I'm asking questions about oils is I haven't got a handbook
and I want to set up before I put the engine in and fire it up in one go without having to leave to get the oil.

Ramona, I have half a tank ( 20 litres ) of fuel with FTC in it. Will this do any harm, or if I put in another
20 litres on top will it dilute it enough to be OK.

No problem, just a waste of FTC. I used to use Caltex 30 grade mono in both engines and the main engines gearbox. I bought 20 litres drums from the company depots. Any tractor supply place should have stock.

Thanks Ramona.

Yes OB I'm just getting the engine supplied. I'd like to do as much as I can installing it, however, I've asked
Sandy Wallace if he'll take over when I hit a snag and finish it off, 'no worries' he said. I was told that these
engines are set up for the 'home mechanic' but I don't know so much. Either way I think I have it covered.