Yamaha 9.9 2 or 4 Stroke

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Inselaffe

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Hi all,

Had to finally admit my 1990 Yamaha 9.9 4 stroke is dead, so have decided to buy a new one.

I have been quoted by a Yamaha dealer here in Lisbon for older (i.e. not this years models), but still new (i.e. unused) motors:

1. Yamaha 2-Stroke 9.9FMHL, manual start, Long shaft, €1745

2. Yamaha 4-Stroke F9.9FMHL, manual start, Long shaft, €2500

The motor in my ETAP 22 sits in a well at the back of the cockpit, and I was very pleased with the old Yam 9.9.

Which of 1. or 2. above would the forum recomend, and why?

I like the quietness of the 4-stroke, but like the price of the 2-stroke!

Thanks
 
Personally, if I were likely to be using the engine for more than about an hour at a time, I would go for the 4-stroke. As you say, much quieter, much less fuel and no oil to worry about. It always was the case that the 4 stroke created rather more electricity as well (worth checking, if it's a requirement). It was also the case that the 4-stroke 9.9 was designed for displacement boats, not sure about the 2-stroke.
 
I have a 10hp 4-Stroke Honda on my 'Snappie' but at the sub 10hp size, i'd still go with a 2-stroke.
At 2/3 throttle, which i'd guess is where you would cruise at, fuel consumption isn't going to be too bad. Also if you have a 2-stroke on your tender, you can use the same fuel for both rather than having a marked jerry can for each.

My biggest issue with the 4-stroke is how cumbersome it is when servicing, cleaning etc.
The cockpit in my Snappie isn't huge and with the weight of the Honda it's a bit of a pain getting it down to look at.
Not to mention that you can only put it down on one side.

Horses for courses, but on a Yacht the deciding factor wouldn't be fuel consumption for me.
 
.

A friend recently sold his new unused 5hp 4 stroke Honda, used for the tender for his yacht, because of the weight - he found it very difficult lifting the engine out of the boats locker and down onto the inflatable, and this sailing yacht has a very large bathing platform. He's now bought a used, (only a few hours of use) 5hp Tohatsu which is much more liftable. 2 strokes are also less complex.
The hassle of mix oil / fuel ratio's can be solved by buying a mixer container which has two halfs, for fuel and oil, and a graduated scale on each for different mix ratio's.
 
A 4 stroke is generally better in a well. 2 strokes can have problems with exhaust fumes building up. Look also at the gearbox ratio and prop size. Bigger, lower pitch prop is generally better for yacht auxilliary. Weight and portability are less of an issue with yacht rather than dinghy motors.
 
Tranona said:
A 4 stroke is generally better in a well. 2 strokes can have problems with exhaust fumes building up. Look also at the gearbox ratio and prop size. Bigger, lower pitch prop is generally better for yacht auxilliary. Weight and portability are less of an issue with yacht rather than dinghy motors.
Click to expand...

I hear what you're saying but my 4-Stroke (which is only 2 years old) isn't smell free in the well (a 2-stroke and 4-stroke exhaust in the same way so what's the difference?) and the weight / portability is an issue when it's time to clean the water intakes / check the anodes etc. I'm no 2 stone weakling but the 4-Stroke is unnecessarily heavy and bulky.
 
Inselaffe said:
Hi all,

Had to finally admit my 1990 Yamaha 9.9 4 stroke is dead, so have decided to buy a new one.

I have been quoted by a Yamaha dealer here in Lisbon for older (i.e. not this years models), but still new (i.e. unused) motors:

1. Yamaha 2-Stroke 9.9FMHL, manual start, Long shaft, €1745

2. Yamaha 4-Stroke F9.9FMHL, manual start, Long shaft, €2500

The motor in my ETAP 22 sits in a well at the back of the cockpit, and I was very pleased with the old Yam 9.9.

Which of 1. or 2. above would the forum recomend, and why?

I like the quietness of the 4-stroke, but like the price of the 2-stroke!

Thanks
Click to expand...

I pretty much face this situation myself & have been mulling it over.....the only positive point I can think of is that with a four stroke you could probably get by with a smaller size compared to a two stroke because they have more talk (spelling):confused:
 
Thanks

Thanks for thoughts from both sides.

I will go for the four stroke mainly because of the previous good experience, smoother, quieter running, no oil mixing, possible exhaust in well problems (presumably for the 2-stroke the oil comes out of the exhaust?), and last, and least, consumption; sometimes with the currents here it is very useful to motor back for an hour or two against the tide.

The weight would not be any significant difference (36 v 41 kg for 2- and 4-stroke respectively), and I only take the motor out once or twice a year (other times I dry out or swim down to the prop to clean it, an advantage of Portugal :) ). I will arrange a way of lifting it up a bit an supporting it to keep it out of the water when the boat is not in use after this 'onions in wallet' experience though, I am a really 'frugal' sailor!

Thanks again

Both have a coil giving max 6A at 12V.
 
Do you need a 9.9 on an etap 22, that seems pretty big, I would be more intrested in the 5-6 hp range single cylinder 4 stroke engines on a boat that size. half the wieght and a resoanble amount of power IMHO.
 
Yes, it is big, but ...

You can expect ebb currents here up to 3 knots, much more locally, especially with a high river flow. Outside the river entrance are big Atlantic swells and nice expanses of shallow sandbanks :)

One time behind Wangeroog Island going out of the Jade in N. Sea Germany I was 'saved' by my 9.9 which (just) held the nose into the gusting F10 wind and enabled me to get home rather than being swept out with the tide into the south east corner of the German Bight. I was kissing the motor Pope-style when we got in, learnt a lot about when to stay in harbour that day :)

Last year when the 9.9 was already loosing a little power we could only just hold our own motoring against the tide rushing out past Oeiras marina. In the end had to turn around, anchor off Praia do Torre and wait for the tide to change before we got back into the marina. Normally no problem, but my wife having early contractions made it a bit more 'exciting'. Now, we have a beautiful 6 month old Crew member, so better too much than too little.

I calculated (using semi-empirical equations in Nigel Calders Cruising book) that to get to hull speed in flat water needs around 8HP. I like to have a bit more for added resistance due to waves and also, importantly, windage.

I got racing out of my system between the ages of 9 and 15, so the weight doesn't bother me!

My outboard is my main engine. I know I am being conservative, but that's how I like it :)
 
kristifercolumnbus said:
I pretty much face this situation myself & have been mulling it over.....the only positive point I can think of is that with a four stroke you could probably get by with a smaller size compared to a two stroke because they have more talk (spelling):confused:
Click to expand...

2 strokes generally have more torque.
 
I have had several small 2 stroke outboards for tenders and messing about and I have always been happy with them but the noise of a 2 stroke on a cruising boat needs thinking about. I have a 25hp Tohatsu, great engine and and which has been totally reliable for seven years/500 hrs and overall overall very pleased with it in every way apart from the noise which is unbearable at anything over light loading. I have tried insulating the cover over the outboard with 50mm sound insulation and also the outboard hood with foam insulation but I have given now up on it and i will get a 4 stroke as soon as finances permit.
A quick flit round the bay, a bit of waterskiing, out to a fishing site etc is fine with a 2 stroke but not several hours pushing into a foul tide and headwind IMNSHO.
 
catalac08 said:
I have had several small 2 stroke outboards for tenders and messing about and I have always been happy with them but the noise of a 2 stroke on a cruising boat needs thinking about. I have a 25hp Tohatsu, great engine and and which has been totally reliable for seven years/500 hrs and overall overall very pleased with it in every way apart from the noise which is unbearable at anything over light loading. I have tried insulating the cover over the outboard with 50mm sound insulation and also the outboard hood with foam insulation but I have given now up on it and i will get a 4 stroke as soon as finances permit.
A quick flit round the bay, a bit of waterskiing, out to a fishing site etc is fine with a 2 stroke but not several hours pushing into a foul tide and headwind IMNSHO.
Click to expand...

I am not sure whether two-strokes are inherently noisier than four-strokes. I can't think of a reason why they would be (which is not to say that there is not one). We have a 25-horsepower Mariner, and it is not noisy. Two-strokes have an inherently smoother cycle so if they are properly muffled I don't know why they shouldn't be quiet. So it might be worth comparing individual motors, without making a blanket judgement.

I love two strokes a whole lot and think they are great marine power units. They have more torque and more power for the same displacement, and are simpler and much lighter. Their efficiency comes from the fact that every piston downstroke provides power, instead of every other downstroke.

They are somewhat less durable than four-strokes because the oiling system is not as effective. Besides that, they used to be subject to ignition problems because of plug oiling, because again because of the oiling system and rich mixtures, but that particularly disadvantage is largely in the past due to CDI ignition systems and better mixture control.

Another concrete disadvantage of them is fuel efficiency; two-strokes inherently waste some fuel-air mixture through the exhaust port, and besides that cannot tolerate a lean mixture. So for auxiliary propulsion of a displacement hull sailing vessel, where the advantage in weight doesn't count and where fuel economy may be very important, four strokes might be worth a look. But I would never consider a four stroke for dinghy propulsion.

Almost all of the disadvantages of two strokes have been solved with the new Evinrude direct injection system. Unfortunately this system is not yet available on dinghy-sized two strokes. I am guessing that situation won't go on forever.
 
Inselaffe said:
Yes, it is big, but ...

You can expect ebb currents here up to 3 knots, much more locally, especially with a high river flow. Outside the river entrance are big Atlantic swells and nice expanses of shallow sandbanks :)

One time behind Wangeroog Island going out of the Jade in N. Sea Germany I was 'saved' by my 9.9 which (just) held the nose into the gusting F10 wind and enabled me to get home rather than being swept out with the tide into the south east corner of the German Bight. I was kissing the motor Pope-style when we got in, learnt a lot about when to stay in harbour that day :)

Last year when the 9.9 was already loosing a little power we could only just hold our own motoring against the tide rushing out past Oeiras marina. In the end had to turn around, anchor off Praia do Torre and wait for the tide to change before we got back into the marina. Normally no problem, but my wife having early contractions made it a bit more 'exciting'. Now, we have a beautiful 6 month old Crew member, so better too much than too little.

I calculated (using semi-empirical equations in Nigel Calders Cruising book) that to get to hull speed in flat water needs around 8HP. I like to have a bit more for added resistance due to waves and also, importantly, windage.

I got racing out of my system between the ages of 9 and 15, so the weight doesn't bother me!

My outboard is my main engine. I know I am being conservative, but that's how I like it :)
Click to expand...

Can't argue with that & it is an interesting post.....like my old mum used to say better to be safe than sorry.
Just one point gleaned from my own experience;I find my boats performance (& my boat is the same size as yours only I should think heavier) is much better under sail than motor.(I once sailed off a lee shore when I doubt my 9.9 Mercury could have handled the conditions).They are auxiliaries & it often galls me when I see people motoring fabulous sailing boats in conditions that I'm quite sure they would be better to sail in.
 
One extra thought... If your old 9.9 is a high thrust version, you could find that the new one may disappoint slightly (The F9.9FMHL isn't high thrust). If the only difference is the gear box, it could be worthwhile swapping them over (if that's feasible).
Good luck
 
I have pasted this from the website of a well known outboard place around here in order to try & clarify the situation.(name removed because I don't want to get involved in advertising).

Buying a New Engine

******* Marine sells the full range of outboard engines. The Company believes that customers should be offered a choice of engines so that they choose the one most suited to their needs. You are able to discuss the different models available and see the range on display. ******* Marine also offers finance facilities for the larger engines.

Part exchanges are welcomed and a wide variety of second-hand and ex-display models are also available to buy off the shelf.

Below are a number of frequently asked questions which may be useful in deciding which outboard will suit your needs.

Short shaft or a long shaft?

The shaft length is decided from the height of the transom which is measured from the top to the keel. A standard shaft is 15"/16" whereas a long shaft is 20"/21". Engines from 3hp upwards are available in short or long shaft. Occasionally an ultra long shaft is needed at a length of 25".

Two or four stroke engine?

The benefits of a four stroke are economy, quietness, smoothness and less pollution. However the initial cost of buying one is more expensive than an equivalent two stroke engine, as is the servicing each year. One disadvantage is that the four stroke engines have oil in the sump and so they have to be laid down a certain way otherwise the oil will drain into the engine, causing considerable damage. They are also heavier and need more attention to the oil level.

Will two stroke engines be banned from 2007?

Outboard manufactures will be required to meet an emissions corporate average based on the emissions from all of their outboard range. So no outboard technology will be outlawed simply manufactures will choose which models to produce across their range.

Which engine is best for my dinghy?

The most popular engine is the 3.3m. Light yet with sufficient power. Allows the user to idle whist waiting to come along side a mooring etc. The 4hp becomes a lot heavier and is less practical if being carried on and off the dinghy. 4 stroke engines are also less practical as they are heavier to carry and harder to store when not in use.

Which engine is best for my yacht?

Most yachts will need a long shaft motor. They will also want battery charging, remote access to the throttle and gear shift and an extra degree of smoothness and quietness, therefore four stroke engines are appropriate. There are also Sail Drive models produced by ****** and ***** which are made specifically for this purpose. 4 stroke engines will still suit yachts which benefit from extra torque for powering a heavy craft. Most sailing boats do not need a big engine, exceptions being large catamarans and multi-purpose boats such as the Macgregor. A 15hp is usually more than adequate to power yachts that need an outboard.

How long do engines run for?

There are several factors which determine running time, e.g. load, RPM. Engines with internal tanks generally run for 20 - 120 minutes whereas those with separate tanks run for several hours at a low RPM and a couple of hours flat out.
 
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