Outboard Motors......

[ozzibod]

Just thought I would enclose a pic of the cutout and the hungry motor.....

Cheers
Austin

P1011002CompV2.JPG (36.69 KiB) Viewed 7072 times

[Miker]

Hi all outboarders.
I am afraid I am not a fan of outboards hanging out on the stern. They can be a target for thieves (you might as well leave a shifter and the hand book and spares). They do not work efficiently and quite frankly they look awful, spoiling the classic lines of the Top Hat! .............snipped..........on the permanent bracket. it just hoists up and down when needed and only comes out for service.

John S "Sombrero"

John, some of us don't actually get the chance to choose. We bought Dulcamara with the current set up and so far have had no issues with it, apart from the asthetics (I don't like it there) and having to strengthen the transom to take the weight and forces the motor generates. It's been on the back of the boat for 5 years and is padlocked in place (Insured as well). There have been occasions where it spins in mid air, but they are rare and not serious enough to warrant a complete renewal of the motor or a change in the set up. I guess I'd rather have it there than have to lift it in and out each time it's required. We also have full cockpit space, because the well is covered at the height of the old bracket, so that's a good trade off too.

If I had have had wanted to spend more money on my first Top Hat, I'd have waited for a diesel, but for $10k I'm prepared to put up with some trade offs.

Looking forward to seeing your set up when you upload the photos....

Michael

[karl010203]

I look forward to the pics it sounds smart !

Hi Karl, thanks for your favourable comments. I am proud of the way my boat is set up and I spend a lot of time thinking of and making improvements. I purchased Sombrero with the outboard lowering system already in place. So I take no credit for the idea. When the wife comes back with the camera I will take some photos, but in the meantime I will give a verbal explanation. From my photo as seen by you, you will notice that the pushpit tubework has been added to to incorporate two tubes that run down to where the old outboard bracket was. A new timber bracket with stainless plates bolted to each side with SS tubing a size up on that used for the upright tubes welded to the plates enables the outbourd bracket to slide vertically up and down in and out of the well. I have a single pulley system for each side and holes drilled in the upright tubes to insert pins ( hanging from light line each side) when the motor is lifted clear of the water. Very little effort is required to lift the motor and it sits comfortably down in the well when running. The vertical posts have flat SS plates at the base which are bolted through the cockpit floor. The rest of the tubework is simply pop rivetted to the pushpit. There are two side braces and two running back to the pushpit itself. The tubework does not interfere with getting in or out of the boat, in fact it makes for a handy place to stand on while boarding.
Regards, John S "Sombrero"

[Swift]

Hi All

On my previous boat I lost the original outboard to thieves one week after I bought the boat. The second outboard lasted six months before it too was stolen. The third outboard was always stowed in the cabin. No way was I going to continue to lift the outboard in and out of the cabin forever, so my next boat was going to have a diesel. I saw a lot of boats with clapped out diesels, or smelly cabins, or oily water in their bilges so I changed my mind and bought a MK 1 with a new 6HP Mercury 2 stroke in a cut out. Upon delivery I changed the outboard padlock for a Stazo Smart Lock. The shiny black Mercury has been proudly sitting on the transom for the past 5 years but so far no takers, I guess the thieves think it's just too much trouble to deal with the Stazo Lock.

The Mercury 6 is ultra reliable and not too noisy so I intend to keep it for a while longer, but when the time comes to upgrade, if cost was no issue I would like to buy something like a Honda 8 or Suzuki 9.9 with electric tilt and electric start, not because I'm too lazy to pull the cord but because with these electric models you get a 12 amp alternator, very useful for those overcast days when the solar panels produces bugger all.

This discussion inspired me to check the fuel consumption, so last weekend I put 5 litres into the tank and motored down the harbour at my usual 3/4 throttle. The tank was bone dry in 75 minutes. This is exactly 4 litres per hour at an average of 5.7 knots. At full throttle I get 6.2 knots and use about 5 litres per hour. dropping down to 5 knots reduces consumption to about 2.5 litres per hour. So the extra .7 knots above 5 knots comes at a cost of a 40% increase in consumption for the same distance covered. The increase from 5 knots to 6.2 knots costs 61% extra fuel.

Before Swifts recent antifoul I used ten litres of fuel in about two hours at a pathetic 5 knots. So putting the two things together: maintaining a clean bottom and keeping speed down to 5 knots results in a massive 100% improvement in fuel economy.

Cheers Keith

[karl010203]

Hey Keith - do you find 6hp enough - I have often wondered if 8hp is overkill never seem to have it above 1/2 way... gets to hull speed pretty quick - but do wonder how it would go with less.

[Sombrero]

Hi Karl and Keith. The photos of Sombreros' outboard lifting mechanism are on the way. We really stirred up a hornet's nest, or was it a swarm of killer bees? Anyway, electric starts and power tilts aside, an alternative to getting charge from a poorly performing solar panel is a good idea. Thus, I find myself blowing a trumpet for my good faithfull Tohatsus. When I purchased my first 5 hp motor for my previous Endeavour 24 and more recently the 8 hp motor that is now in, ( sorry! not on the back of!) Sombrero, I had both fitted with a charge unit that is incorporated with the flywheel (a standard Tohatsu optional extra costing from memory an extra $160. Some dealers call it a lighting unit.). This unit puts out about 18 volts, measured by me, but not a heap of amps. Because of the Solar also feeding in my case, a large gell battery, it is necessary for the output of the charge unit to have a regulator between it and the battery.I only use battery power for lighting and nav. aids. My Tohatsu is manualstart.
At the risk of making a few enemies, I hasten to point out, that be it inboard or outboard, it is an auxhilliary form of propulsion for use when the wind fails or the tide becomes too much. I for one would be spending my money on new sails or updating spars and rigging. There are around a dozen 22 ft. Bluebirds at my club and some of them still use the old aircooled rope pull Seagull outboards for propulsion. I rest my case. For now!
Cheers. John. S Sombrero.

[Tales]

Just to add my two bob's worth!
When I investigated replacing my 4hp Suzuki two stroke (which performed quite well but was noisy and smelly!) I found that the Suzuki 6hp four stroke has an 80w (aprox 6.5 amp) battery charger as an option.
It was explained to me that competitors charge units actually 'steal' power from the ignition coil once the engine revs rise enough not to cause a problem and give modest charge.
The Suzuki unit cost a bit more as an add-on because you have to buy a new flywheel as well however the unit charges from idle upwards.
I have found the DF6 great but as I have mentioned before, the prop I use is from the DF4 which is finer pitch allowing the motor to rev enough to develop its 6hp potential.
Cheers,
Tom

[Swift]

Hi All

Tom, it’s interesting you mention "stealing" power from the ignition circuit, a while ago I was talking with a guy who has done a lot of miles in a Top Hat about the fact that I had no charging or “lighting” kit on my outboard. His advise was to stick a multi-meter on the motor and see what power I could get, if it looked useful just hook up some wires to the battery with a 12v car regulator in between. He says it has worked well for him over the years but as yet I have not been game to try it. Also, you make a good point about having the right prop size to allow the motor to rev. I think mine is right but a rev counter would be a really useful accessory.

Karl, to answer your question, so far I have never wanted more than 6HP. This is enough drive a Top hat at hull speed in reasonable conditions so I think it’s a good compromise between weight, power and cost. For my needs it would be absolutely perfect with a 40-amp alternator bolted to the side! Having said that, I must add that I am with John in my attitude towards motors and tend to keep sailing despite failing winds or adverse conditions, I sort of feel like I have admitted defeat when I give up and turn the motor on, even to the extent of the potentially tricky business of sailing on to my crowded for and aft mooring. Lately I have been trying to break the habit and use the motor more because I am so often late!

It’s comes down to personal needs. Some folk like to drop sail and motor when the wind gets up, and if one day I felt inclined to motor into the teeth of a 30 knot near gale I would be happy to accept 3 knots full throttle while others might find such slow progress intolerable. At over 35 knots would a 6 HP be of any use going to windward? 8 HP or 10HP would obviously be better. At 40 knots is a motor of any size of any use going to windward? I don’t know. It would be interesting to hear from anyone who has been in a Top Hat in 40 knots sustained either under power or sail.

As a follow up to my economy test last week I went out on the harbour on Wednesday and did an accurate test at 5 knots. The result was surprising, only 1.71 litres per hour. That’s much better than my estimation of 2.5 litres per hour. Obviously the motor must be doing less than half revs. I might add that this was the nominal speed, (sheltered water) not distance made good. At these low power settings the wind and current have a big effect, with a breeze of less than 10 knots and the throttle at my nominal 5 knot setting I achieved 4.8 knots upwind and 5.2 knots downwind.

It's logical when you think about it, I read somewhere that at low speed frictional resistance is the most important component of hull drag, but once over the ratio of 1 (square root waterline length), wave-making resistance takes over, and at a ratio of 1.1 wave making resistance begins its ever steepening rise up to the notional hull speed ratio of 1.35. So power requirements are rising exponentially from 1.1 to 1.34. It just happens that for a Top Hat 1.1 X 4.53 = 4.983 knots.. So while 4.5 knots is very economical the additional ½ knots to 5 knots has only a small proportional impact on fuel consumption so it’s a good compromise between economy and a reasonable speed. It’s useful information if you’re trying to make it home and your short on fuel.

Cheers
Keith

[Sombrero]

Hi Keith, I had just about finished a very lengthy tale in response to your post ( When my screen went blank! So, here is the abbreviated version!) It was about how my friend and I were competing in an 18 nautical mile two handed race on our bay recently, which started in lovely sunshine and very light wind, when we were hit by a south easterly gale, blinding rain, seas growing rapidly to 2-3 metres and wind to 40+ knots. When it hit we had full main and the mylar/kevlar genoa flying and were sailing hard on the wind. We reduced sail to No.2 and one reef, then two reefs. We really should have gone down to the No.3 but staggered on making 3-4 (and sometimes 5) knots to wind figuring that we would soon be on the 8 mile run to home. Which turned out to be a series of long reaches because it was too dangerous to run square as the boat was trying to plane and the bow was burying rather frightenly.
When we were on the wind,the seas were steep and breaking and frequently throwing us off course. I was worried about the mast and rigging but the boat handled it beautifully. I have been in races in Bass Strait on bigger, fully crewed boats and felt less confident than I did on that day in the tough little Top Hat. I asked my friend whether he would like to be in the middle of the ocean doing it by himself. His response cannot be printed here! Which brings me to what I really intended to write about. With regard to experiencing wild weather, it is worth revisiting General Discussion: "White Tie Sold" Post by Storm Petrel: Tasman pdf. Log of White Tie skippered by Nick Creech in the 1978 Trans Tasman. That man and his boat, one like ours really saw some very bad weather! It would seem, that providing they hold together, a Top Hat can go through anything.
Given the wind and wave conditions we experienced on the day we raced, I believe we were much safer in continuing to press on under reduced sail than we might have been, had we done what some the retirees did in dropping their sails and trying to motor home.
John S. "SOMBRERO".

[Swift]

Hi John, it sounds like that race was real fun! From your description I imagine that the typical Southerly gale looses some of it's punch by the time it arrives in Sydney. The last one I was in was about a month ago, at night, and it provided some exciting sailing. I thought that my impression that the winds were a bit higher than usual was just that - an impression rather than a reality due to sailing in darkness. I later checked the actual records for the day on Sea Breeze and found that it was 40 knots, but that was only for the first ten minutes, then it settled down to 30- 35 knots. This was the first time I had thought to verify the wind speed and this confirmed my estimate of other near gales I had been in, and while they were maybe more sustained not one of them had exceeded 40 knots. For anything more exciting, I hope only to experience it vicariously, so thanks for your detailed response.

Also thanks for reminding me of White Ties race across the Tasman. It was worth re-reading.

Cheers
Keith