Temorarily Underpowered

Temorarily Underpowered

Postby Swift » Wed Apr 11, 2018 6:39 pm

Last weekend I had arranged to have my boat slipped at Central Coast Marina in Booker bay. On Friday as I approached the Rip Bridge the outboard motor revs suddenly increased while the boat came to a stop. The rubber bush on the propeller had sheared. Fortunately the guys at the marina were happy to give me a tow. I would have liked to spend the afternnon working on the baot but instead ran around looking for a replacement prop. I was lucky to call into Advanced Marine Repair who pulled a prop off an old 5hp motor and generously lent it to me at no cost.

On Monday morning Swift was back in the water with fresh antifouling. It was 1.5 hours after low tide so I was with the tide until I got to the overflow at the Rip bridge, At first I seemed to be making good progress but by the time I was directly under the bridge I could not make any further progress due to the slightly smaller 5hp prop on my 6 hp. Usually I just manage to crawl through this patch. Anyway it was a nice day so I picked up a mooring the other side of Booker bay and had a relaxing lunch while waiting for the tide. As a matter of interest Swift will usually do 6 knots with fresh anti-foul. The top speed with the smaller prop was 5.3 knots.

My Mercury 6HP is 14 years old and has been extremely reliable, but I think that the prop failure is a warning that its getting old I cant imagine what would have happen if I had a motor failure coming around Half Tide rocks. So I think it's time for a new motor, probably another lightweight 2 stroke Mercury or maybe a Tohatsu which is virtually the same motor. Both of them are available in 9.9 HP at the same weight as my existing 6. Do any of you other outboard owners have comments or suggestions?
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Re: Temorarily Underpowered

Postby Miker » Thu Apr 12, 2018 10:31 am

Hey Swift, That area can be difficult when you get engine problems.

I've got the 4 stroke 8hp Tohatsu. I think it's a 2004 model, so same age as yours. It still looks new under the cowling and starts within 3 pulls even after months of not being used. It doesn't fit in the well, so is over the back on a bracket. Not ideal, but it's always worked well enough. Not long ago, I got a Solas 4 blade high thrust prop. It changed the boat speed and reversing ability as well. The original 3 blade had the engine labouring to reach optimum revs, but I could still pull 5.0 knots with a dirty bum. The 4 blade feels much better, and gives much better response, and the engine can reach optimum revs. I'd say I get almost hull speed of 6.8 at full revs, but I cruise just under 6.

I've been in and out of Brisbane Water against the tide, rather than with it and been able to make way without any dramas. The engine shows no sign of wear, doesn't use oil and gets a full service every two years, because it's only used for 20 minutes at a time mostly. It does get a basic oil and filter check every two or three times out though.

If it was me, I'd be making sure my existing engine is serviced well, and has the water pump serviced, new plugs and fuel filter. Keep spare plugs at all times. If it blows lots of smoke, is hard to start or misses and carries on, perhaps a rebuild is going to be cheaper than a new engine, plus you know what you have.

Then get yourself the 4 blade and you should be right for many years.

If you go the new engine route, go Yamaha T9.9 Expensive, but apparently the best for the job.
Hope this helps,
Michael
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Re: Temorarily Underpowered

Postby Swift » Sat Apr 14, 2018 1:44 pm

Michael, thanks heaps for your comments. I remember admiring the Tohatsu on Dulcimer at the last Top Hat event I saw you at.

I googled the Yamaha T9.9 you suggested and your right it looks perfect (apart from the extra weight) but as you note it’s not cheap. My concern would be that it could be a thief magnet. Considering your Tohatsu is on a leg what do you do for security? A chain and padlock? . Another thing I am considering is that I suspect that the cockpit floors on Mk 1’s are a bit lower than on later models making them more sensitive to weight on the transom….. mmm your detailed advise has certainly given me a lot to think about.

Cheers, Keith
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Re: Temorarily Underpowered

Postby Phillip » Sat Apr 14, 2018 5:45 pm

Another thing I am considering is that I suspect that the cockpit floors on Mk 1’s are a bit lower than on later models making them more sensitive to weight on the transom….. mmm your detailed advise has certainly given me a lot to think about.


You are right Kieth, the Formit Top Hats have the cockpit floor 100mm above what you find in the Mark 1.

As to what you mean by "more sensitive to weight on the Transom" I'm not sure.
If you mean strong enough I can assure you that the 10mm thick transom is very strong!
Phillip.
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Re: Temorarily Underpowered

Postby Swift » Sat Apr 14, 2018 6:39 pm

Phillip, thanks for confirming the hight diference in the cockpits. Wow! 100mm that's much more than I guessed.

I wasn't concerned about strength, just thinking of buoyancy and weight distribution. I don't know about your mk 1 (because they vary a bit) but with mine, at hull speed with full tank of water (130KG) , some extra fuel, a few people aboard Swift starts dragging her bum and I get water in the cockpit. Not a big deal but just trying to minimise it. To be honest the bigger concern is just the weight of the outboard when its time for a service. Not getting any younger!

Keith
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Re: Temorarily Underpowered

Postby Phillip » Sat Apr 14, 2018 10:09 pm

Well, all Top Hats will drag their bums, it seems we are lacking about a foot in waterline length at the stern.
In fact two, that I know of, have added just that in the form of a sugar scoop.

BUT, if you strip the yacht of all gear, except safety gear of course, you will find a very different yacht, almost like a large dinghy!! :D :shock:
Phillip.
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Re: Temorarily Underpowered

Postby Phillip » Sat Apr 14, 2018 10:11 pm

Oh, and that's why Mark 1'ers have sea boots :lol: :lol: :lol: :lol:
Phillip.
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Re: Temorarily Underpowered

Postby Miker » Mon Apr 16, 2018 11:16 am

Swift wrote:Michael, thanks heaps for your comments. I remember admiring the Tohatsu on Dulcimer at the last Top Hat event I saw you at.

I googled the Yamaha T9.9 you suggested and your right it looks perfect (apart from the extra weight) but as you note it’s not cheap. My concern would be that it could be a thief magnet. Considering your Tohatsu is on a leg what do you do for security? A chain and padlock? . Another thing I am considering is that I suspect that the cockpit floors on Mk 1’s are a bit lower than on later models making them more sensitive to weight on the transom….. mmm your detailed advise has certainly given me a lot to think about.

Cheers, Keith

The Tohatsu has the normal screw clamps up most portable outboards have. I just have the two swinging handle thingies pointing to each other and have a padlock joining them. Last time I took the motor off, I had to cut the padlock, as I'd either lost the key or it had seized. Can't quite recall which. The other thing I do is keep the engine cowl covered with a Whitworths outboard cover. That way it doesn't advertise the brand.

The other thing about sail specific outboards, is that they have a longer leg, so not all that attractive to thieves.

There is also a way to use through bolts instead of the standard of the clamps. Bolts are harder to undo quickly and you can also add a chain if you're worried.

The worst thing about the outboard over the back is that I don't have any cockpit controls, I have a long bit of conduit over the gear lever and need to reach the twist grip when maneuvering. That being said, I've only ever hit two things, the Careel Bay Wharf when I couldn't get reverse quick enough in a strong northerly, and Swift when we were leaving the basin that day :shock: That Sailaway was in 2009!

If you want to see how it all works, let me know when you're free to come up to Careel and I can take you for a spin.
Michael
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Re: Temorarily Underpowered

Postby Phillip » Mon Apr 16, 2018 5:56 pm

Rule two when you have your outboard on the stern:

As Mike said.......The worst thing about the outboard over the back is that I don't have any cockpit controls,
I have a long bit of conduit over the gear lever and need to reach the twist grip when maneuvering.


Always have a spare in case you loose one overboard just before a solid object :lol: :lol: :lol: :lol:
Phillip.
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Re: Temorarily Underpowered

Postby Miker » Tue Apr 17, 2018 12:08 pm

Phillip wrote:Rule two when you have your outboard on the stern:

As Mike said.......The worst thing about the outboard over the back is that I don't have any cockpit controls,
I have a long bit of conduit over the gear lever and need to reach the twist grip when maneuvering.


Always have a spare in case you loose one overboard just before a solid object :lol: :lol: :lol: :lol:


Well you may giggle Mr Phil, but I have my piece of conduit tied to the pushpit with a nice bit of spectra..... I also have a nice length of spectra between the pushpit and the lifting handle of the outboard, just in case anything happens to the bracket and the motor falls off :shock:

I wish I had have had the same idea when I lost two pairs of other people's tongs overboard on that sailaway..... :lol:

To be fair, when I hit the jetty, I was in a 30 knot nor easter that was pushing me on. I doubt any kind of controls could have saved the boat from my complete brain fade on that day..... :? :oops: It's also what made me go get a 4 blade hi-thrust prop!
Michael
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