Outboard Engines
Another problem that keeps cropping up on various small boat web forums is outboard engines and outboard engine mounts. I am sure that our solution will not suit everyone but it does have an awful lot going for it. To start with we use a Seagull Century Plus longshaft engine, not everybody’s first choice but consider the pros and cons.
For.
Cheap to purchase
No recoil starter to get broken.
Very simple to maintain (fuel system can be completely striped, cleaned & rebuilt in under 5mins, spark plug & lead in about 2mins.)
These engines were built to move displacement boats, unlike modern 4 stroke or 2 stroke engines, ours has a 9” prop and will happily move Casulen II along at a steady 4.5knots.
They were designed to run for prolonged periods under this load, again we have motored for over 12 hours non stop once in order to get home one weekend.
The longshaft fitted to our outboard mount very rarely ever lifts out of the water.
Overall weight of the engine about 18kg compared to about 26kg for a 5hp longshaft 4 stroke.
Against
10:1 fuel/oil mix although you can modify them to run at 16:1, 20:1 or even 25:1 on later engines.(ours runs on 16:1)
No charging coil like on a sail drive
No recoil starter (may bother many people)
No reverse gear
More noisy than a 4 stroke
I’m not going to argue for or against this choice only to say it seems to work for us. Our engine is a 1964 model so it is nearly 3 times as old as I am and it is still running reliably!
Our outboard bracket design would suit any outboard, not just Seagulls and has no pivot mechanism but slides up and down on two parallel tubes. It was made up out of 316 stainless tube and rail fitting, (easily obtainable from marine suppliers) and our old outboard mount.
To start with it was bolted together, but we have now had all the joints welded having proved that the idea works. Its main advantages are that all the weight is kept as close to the transom as possible and the engine stays in a upright position even with the prop fully clear of the water.
Due to the range of height adjustment the prop can be dropped deeply into the water so does not lift out in big seas. Our adjustment is a simple bracket with a length of cord knotted at various lengths.
In order to give us long range we use a 25ltr tank mounted in the cockpit and simply attach a tube via an outboard tank fitting and pump the fuel through by hand via a priming bulb. 
As I said this arrangement is simple and has enabled us to cover over 2800nm in two seasons through some quite interesting tidal waters on the West and North coasts of Scotland and also in the Irish Sea and around both the North and South Cornish Coast.
Jonny