I get a bit worried when I see owners saying that this or that Norman was made to take up to a 50, 75 0r 100hp outboard. Outboard in the past (when Normans were in production)were all rated at the crankshaft less the extra load of the shaft, water pump and gearbox and were almost all two strokes that weigh a lot less that the modern four stroke engine, the modern engines are rated at the prop and produce around 20 to 25% more power, so should we not be down grading the engine size taking in these factors? I think the weight is the most worring factor. Len.
I don't think ANYONE on here is going to stick a 100hp motor on the back as it would cost an arm, leg and both kidneys to run it! Most of them seem to run with Honda 7.5's up to 15hp as they stick to rivers and canals. Even a 40hp at WOT wants 20 litres an hour and at £1.36/litre that's a lot of money!
You've probably got a good point though but frankly a 20 would plane with 40hp up, comfortably with 50-60hp and I don't think anyone would want to put any more on the back of an old transom anyway.
Come to that, YOU wouldn't - looking at your other post!
Edit - it's not the weight that is the issue, it's the rotation forces a big motor exerts on the transom that is of more concern.
The cost of boating is insignificant compared to costs of a young wife and two teenage kids!
Outboard sizes
Posted - 03 Jul 2011 : 18:54:51
