The 8hp Yamaha two stroke motor is a bulletproof motor and the cheapest and lightest way out. Fuel economy and having to mix oil are the only drawbacks. If you go for the Yamaha four stroke you will not have these drawbacks. But you do have to watch the engine oil and service cost are higher and more regular. There is not much to service in a two stroke apart from a bit of grease, pump impeller and may be a couple of spark plugs.
The main thing is to make sure that you have the correct propeller for pushing a yacht. The standard propeller that come with the motors are designed to push a 12 foot tinny at speed. I have had a Honda 15 and was not a great fan. At the end of the day it will be a hard choice between the two and four stroke, but I don't believe you will go wrong with either.

I'm pretty happy with my Yamaha 9.9hp 4 stroke. It pushes my Spacesailer 24 along at an easy 5 knots in most seastates and is easy to flush as it has a proper flushing port.

If you intend on using your motor a fair bit, a quiet engine is a must, and a 4 stroke delivers this. My motor is almost silent when it's at idle.

AshleyM said..
Jode5: can you recommend an honest local who can service my outboard, preferably at the pontoon down at the Redcliffe Jetty? It's due for a service and I'm not really ofay with outboard engines, and if I could avoid a day sail to the marina it would save me time. Cheers

Sorry Ashley, can't help with that one. I use Northside Marine, but not sure about their cost for onsite service.

Two stroke will be lighter and easier to transport for servicing. Four stroke motors have to be stored the right way. I would consider other brands as well if you are buying new. Avoid the Chinese ones perhaps though who knows where the Japanese motors are really built. I would suggest watching the secondhand motors in the 6 to 8hp range on eBay and Gumtree for awhile and see which ones are in demand and sell the best. Watch reviews on Youtube.

I have a Top Hat 25 and run an 8hp Tohatsu 4 Stroke. It's been on the back of my boat since I bought it in 2009. Serviced every year by draining oil, replacing spark plug. Every three years it gets a new impeller. It's never been flushed, apart from the annual service. Takes three pulls to start and will take an electric start and charging system if you're that way inclined. It pushes the Top Hat at 6 knots in most conditions and has driven me back to Sydney from Lake Macquarie when the wind petered out. Although I check the oil regularly, it never needs a top up between services.

Although that's my only experience with small outboards, the above makes me think I'd get another if ever this one dropped dead. The Tohatsu website has all the technical details you'll need for servicing.

The only thing I'd check if you're on a 23 footer, is the weight of the engine for your needs to lift it, and prop size suitable for the weight and draft of your boat.

cisco said..
It really depends on what your "23 feet fixed keel sailing boat" is.

I had a 23 foot fixed keel sailing boat which had a 4 hp single cylinder 2 stroke Mariner/Mercury outboard on it which pushed it along at 7 knots + with a standard prop.

As Professor Julius Sumner-Miller said "How is this so??"

More information. The yacht was a "Windrush Wildfire". The other end of the yacht scale might be a Roberts Adventure 23/25.

More information please for a more qualified answer.

What yacht do you have??

Special song for you Lolita.

Thanks, cisco. My boat is a fibreglass Hood 23. 7.2m length, 2.5 m beam , 1.35 m deep. 1.8 ton.
Also Thanks for the lovely song/video ! :-))

AshleyM said..
I'm pretty happy with my Yamaha 9.9hp 4 stroke. It pushes my Spacesailer 24 along at an easy 5 knots in most seastates and is easy to flush as it has a proper flushing port.

If you intend on using your motor a fair bit, a quiet engine is a must, and a 4 stroke delivers this. My motor is almost silent when it's at idle.

Thanks, AshleyM. This is a great feedback. I will get my current Yamaha fully checked out to see off there is some more life left in it. If not I might go to 9.9 4 stroke (also depends how much is the new one !!:-(( )

Trek said..
Dont forget to get a long shaft version of whichever motor you choose so if the boat pitches a lot in seas the prop stays in the water.

Thanks, Trek. I am definitely looking at the long shaft ones. Cheers.

Have a 5hp 2stroke Yamaha on my 28foot boat I want to replace it with a 4stroke as it is to noisy. Most of the time it is running at 1/4 throttle.

For you I would be looking at a Yamaha 4stroke with the correct prop. How often do you run the current motor flat out??? Dose it need to be an 8???

I would go for the Tohatsu 4 stroke 6hp sailpro version. It will have plenty of thrust, ticks over nicely, and is just light enough to lift out and stow below deck. The extra long shaft is great for when you hit ocean chop and the boat starts to hobby horse. It solves to a large extent this main problem with transom mounted outboards.

Oh, and keep your washboards in and secured when sailing offshore. Sad history there.

dkd said..

Lolita, my input for what it may be worth.

I have 26 foot deep keel yacht and we run a long shaft 5hp 4 stroke Honda with standard issue prop. It pushes the boat along at about 6, maybe 6 and a bit knots at about 3/4 throttle.

Yes it tilts up, yes it has plenty of clearance over water and maintenance it dead dead simple. Starts first time every time and no complaints at all.

Light enough that we take it off every time we return to the marina and put it downstairs (I dont trust anyone enough to leave it hanging on the transom)

In the end, it is what works for you, you are a little heavier than us (300kg heavier) but we are 2.4m draught, 8m long and about same beam

There are plenty of choices but as a marine engineer there are plenty I would avoid too. IMO look seriously at the Honda but remember it is your decision.

Thanks, dkd. I will do a bit more search on Honda 6 HP 4 stroke and Yamaha 6 or 8 4stroke. Prices, dealer service close by, weight, etc.etc. I am going to make a spread sheet - have to I think.
Hard call....but thanks again for the advice/feedback.

lolita said..

AshleyM said..
I'm pretty happy with my Yamaha 9.9hp 4 stroke. It pushes my Spacesailer 24 along at an easy 5 knots in most seastates and is easy to flush as it has a proper flushing port.

If you intend on using your motor a fair bit, a quiet engine is a must, and a 4 stroke delivers this. My motor is almost silent when it's at idle.

Thanks, AshleyM. This is a great feedback. I will get my current Yamaha fully checked out to see off there is some more life left in it. If not I might go to 9.9 4 stroke (also depends how much is the new one !!:-(( )

The list prices for the high thrust versin on the 9.9 4 stroke is around $3500, more for remote throttle and electric start, which is what mine is. My motor weighs just under 50kg so it is generally not portable in any way. Mine lives on the back of my boat and is secured by a robust s/s padlock.

Looking at the Tohatsu Sail Pro, it is almost half the weight, but I guess it's only producing slightly more than half the power.

I've always been a little scepticle about outboards pushing keel boats, what will push you along at 5 knots in calm weather probably won't do the same in heavy weather. My 9.9 set to half throttle, and my hull set to clean mode, generally pushes me along at 5 knots in every weather state I've used it in and it rarely cavitates, except in 20+ knot conditions in a wind against tide situation.

In saying that, when I was a teenager my dad's yacht had a Yamnar YC12 which damn could damn near literally shake the fillings out of your teeth, so in that respect the low price of a good quality, quiet 4 stroke outboard more than outweighs the blight that they are to the transom of a yacht, especially when motoring for hours on end during an windless Moreton Bay winters day.

AshleyM said..

lolita said..

AshleyM said..
I'm pretty happy with my Yamaha 9.9hp 4 stroke. It pushes my Spacesailer 24 along at an easy 5 knots in most seastates and is easy to flush as it has a proper flushing port.

If you intend on using your motor a fair bit, a quiet engine is a must, and a 4 stroke delivers this. My motor is almost silent when it's at idle.

Thanks, AshleyM. This is a great feedback. I will get my current Yamaha fully checked out to see off there is some more life left in it. If not I might go to 9.9 4 stroke (also depends how much is the new one !!:-(( )

The list prices for the high thrust versin on the 9.9 4 stroke is around $3500, more for remote throttle and electric start, which is what mine is. My motor weighs just under 50kg so it is generally not portable in any way. Mine lives on the back of my boat and is secured by a robust s/s padlock.

Looking at the Tohatsu Sail Pro, it is almost half the weight, but I guess it's only producing slightly more than half the power.

I've always been a little scepticle about outboards pushing keel boats, what will push you along at 5 knots in calm weather probably won't do the same in heavy weather. My 9.9 set to half throttle, and my hull set to clean mode, generally pushes me along at 5 knots in every weather state I've used it in and it rarely cavitates, except in 20+ knot conditions in a wind against tide situation.

In saying that, when I was a teenager my dad's yacht had a Yamnar YC12 which damn could damn near literally shake the fillings out of your teeth, so in that respect the low price of a good quality, quiet 4 stroke outboard more than outweighs the blight that they are to the transom of a yacht, especially when motoring for hours on end during an windless Moreton Bay winters day.

Very good info here AshleyM. Many thanks. Couple of questions if I may:
How would you get the heavy 9.9 out of the boat for the yearly service?
You don't have to worry about that because service guys do it?

Cheers,

lolita said..

AshleyM said..

lolita said..

AshleyM said..
I'm pretty happy with my Yamaha 9.9hp 4 stroke. It pushes my Spacesailer 24 along at an easy 5 knots in most seastates and is easy to flush as it has a proper flushing port.

If you intend on using your motor a fair bit, a quiet engine is a must, and a 4 stroke delivers this. My motor is almost silent when it's at idle.

Thanks, AshleyM. This is a great feedback. I will get my current Yamaha fully checked out to see off there is some more life left in it. If not I might go to 9.9 4 stroke (also depends how much is the new one !!:-(( )

The list prices for the high thrust versin on the 9.9 4 stroke is around $3500, more for remote throttle and electric start, which is what mine is. My motor weighs just under 50kg so it is generally not portable in any way. Mine lives on the back of my boat and is secured by a robust s/s padlock.

Looking at the Tohatsu Sail Pro, it is almost half the weight, but I guess it's only producing slightly more than half the power.

I've always been a little scepticle about outboards pushing keel boats, what will push you along at 5 knots in calm weather probably won't do the same in heavy weather. My 9.9 set to half throttle, and my hull set to clean mode, generally pushes me along at 5 knots in every weather state I've used it in and it rarely cavitates, except in 20+ knot conditions in a wind against tide situation.

In saying that, when I was a teenager my dad's yacht had a Yamnar YC12 which damn could damn near literally shake the fillings out of your teeth, so in that respect the low price of a good quality, quiet 4 stroke outboard more than outweighs the blight that they are to the transom of a yacht, especially when motoring for hours on end during an windless Moreton Bay winters day.

Very good info here AshleyM. Many thanks. Couple of questions if I may:
How would you get the heavy 9.9 out of the boat for the yearly service?
You don't have to worry about that because service guys do it?

Cheers,

According to the Yamaha website, the 9.9 4 stroke is 40kg in the long leg version. I think most of the reputable 4 strokes of that size are roughly the same. I'm 58, 85kgs and reasonably fit, and can lift my Tohatsu 4 Stroke 8hp off into a dinghy no trouble. Just use a halyard with the slack taken up to prevent a dunking if you slip or fall. If you're in a pen, it should be even easier. With two people it's a doddle.

Easier still, learn how to service it yourself and do it on the boat. It's really only a 30 minute job at most.

I would like to put a word in for learning to service your own outboard. I think any self respecting owner, who sails offshore or along the coast, should be able to change spark plugs, clean carbys and change an impeller. It is not rocket science at all and most outboards will run fine if you do these three things. You can change the impeller when you change the oil during slipping. Plugs and carbys should be cleaned whenever the motor runs rough. If you want to learn watch Dangar Stu. He has a great channel on outboards. I watch him all the time. Throw him a dollar by buying a shirt. Don't pay someone to service your outboard when it is much safer to be practiced at it yourself.

The forum won't allow me to insert a hyperlink so go to Youtube and search for Dangar Marine.

cheers

Phil