by Dolphin » Sun Jun 10, 2012 9:58 am
Rod,
I raced on a Mk 1 Top Hat on Sydney Harbour with Sydney Amatuers, That boat had an outboard in the transom cut out and we used to motor from Lane Cove R to the bridge and then move the motor to the cockpit locker where it stayed. We'd sail home. It wasn't a big problem but I can't remember the size of the motor. Maybe I was younger and fitter then too.
I had a Cole 23 with a 9Hp Chrysler, pull start, on an offset transom bracket. That is the WORST way to mount a motor. Mike's setup on Dulcamara works well.
I've got a 12HP Volvo diesel, it replaced a BMW (Hatz D12). I think it is heavy. It is certainly powerful but at full throttle it buries the bum of the boat in the water to the extent that the water level in the cockpit comes up to the rudder stock. Does this happen with outboards?
Be aware that the BMW's are getting old. They're great as a piece of farm machinery but they give a lot of trouble if they've not been looked after. I'm sure they happily pump water from the Danube on Fritz's farm all day long but they weren't meant for marine applications.
The mixing elbow (exhaust manifold) on the Hatz rusts out about every 5 to 7 years. It costs, are you sitting down, $ 874.95. I broke a head stud and the alternator wasn't working. That made me change the motor. THe Volvo cost $10k and installation was $4k.
BMWs also have a design flaw where the alternator is a motorbike, and outboard, style alternator (made by Ducati) under the flywheel with permanent magnets. Water leaks from the O rings around the head studs and runs over the alternator and rusts the laminations. They then expand, cutting the wires and jaming the flywheel. The only way to fix it is to remove the engine and then the gearbox and flywheel.
The list of pros and cons goes on for either side. Nothing is perfect.
The biggest decider for me was the flamability of petrol compared to diesel.
Hope it helps.
Greg
Felicite Mk III
Lake Macquarie
"After it's all said and done, there is a lot more said than done!" Aesop 620 BC