Outboard decisions: 2 vs 4 strokes

[Adelie]

Power and weight are not the only considerations, just the normal considerations.

New 2-strokes are harder to service in the US.

If you are going where fuel supply may be limited, then the 4-stroke may be the better option, they get about 50% better fuel economy.

In pollution is a consideration for you then 4-strokes are the better option.

If you want to get the lightest weight engine possible, then a 2-stroke is the better option. Not just because it is lighter for a given horsepower, but because it has better midrange torque and you can use a lower horsepower engine to get on a plane, so depending on the particulars of your dinghy and loading you can get an even lighter motor.

Depending on where you intend to cruise, it may be hard to get parts and service for one type of engine or the other.

If don't feel that you ever need to plane the dinghy, then an electric trolling motor may be the better option than a 2-stroke or 4-stroke.

[CarlF]

A brand new 2 stroke certainly puts you in the "don't give a F#@k about climate" group. Doesn't bother some but I'd never do it.

As said - buy only EFI four strokes. I believe the Honda is still carburated. My last one was a nightmare from carburator fouling. The EFI's start more easily and run smoother than any carburated outboard - 2 stroke or 4 stroke. And the lower gas consumption is really noticeable.

Do you want electric tilt? Only really important if the RIB will have a steering wheel (something your wife will never let you give up). Not all 20hp are available with an electric tilt. Also be sure the outboard is the right for the transom height. Highfield offers two heights on some models.

After actually trying the different models I chose a Suzuki over Yamaha or Tohatsu four stroke. While Yamaha Enduro 2 strokes were legendary Yamaha never quite got their act together on four strokes. Noticably more vibration and noise than my Suzuki.

Suzuki now seems to be the most common new small outboard in The Bahamas. Lots of service available - not that I've ever needed any.

[Sailing Hanse37]

Originally Posted by s/v Jedi

Hoi Pepijn, mooie boot!

We had to make the same decision a couple years ago and the answer is easy: get the new Mercury 15 or 20hp with 4-stroke, EFI and the new multi tiller handle, see attachment.

We have the CL320 so we went for the 20hp. Seeing they are the same size and weight, you may consider the 20 as well.

There is one reason to go for the Tohatsu instead and that is the lower price. It is the same motor but it doesn’t have the new tiller arm which is really, really nice.

For a 2-stroke, you need to bring 3-4 times as much gasoline and mix oil into it etc…. and deal with carburetors

It is true that 2stroke consumes a bit more gasoline than a 4stroke, but 3-4 times ? it will probably consume 20 to 30 % more and that’s it

[Sailing Hanse37]

Originally Posted by CarlF

A brand new 2 stroke certainly puts you in the "don't give a F#@k about climate" group. Doesn't bother some but I'd never do it.

As said - buy only EFI four strokes. I believe the Honda is still carburated. My last one was a nightmare from carburator fouling. The EFI's start more easily and run smoother than any carburated outboard - 2 stroke or 4 stroke. And the lower gas consumption is really noticeable.

Do you want electric tilt? Only really important if the RIB will have a steering wheel (something your wife will never let you give up). Not all 20hp are available with an electric tilt. Also be sure the outboard is the right for the transom height. Highfield offers two heights on some models.

After actually trying the different models I chose a Suzuki over Yamaha or Tohatsu four stroke. While Yamaha Enduro 2 strokes were legendary Yamaha never quite got their act together on four strokes. Noticably more vibration and noise than my Suzuki.

Suzuki now seems to be the most common new small outboard in The Bahamas. Lots of service available - not that I've ever needed any.

We live fulltime aboard our board and have a Tohatsu 5hp, 2 stroke. We use between 10 and 15 litres of gasoline per year. The climate difference is not worth talking about…

[MicHughV]

I think it's all a moot point. There are countless of 18 wheel trucks on US roads, hard to miss sometimes, when you see a cloud of black smoke coming out of the exhaust when changing gears, etc...a single Boeing engine burns about 60 gallons/minute.....etc..etc..etc...

[Adelie]

Originally Posted by MicHughV

I think it's all a moot point. There are countless of 18 wheel trucks on US roads, hard to miss sometimes, when you see a cloud of black smoke coming out of the exhaust when changing gears, etc...a single Boeing engine burns about 60 gallons/minute.....etc..etc..etc...

Boeing doesn’t make engines, their planes use engines made by others.

[MicHughV]

picky..picky....ok...GE or Rolls engines...

[rslifkin]

In my mind, the biggest advantage to a more efficient is that you don't need to carry as much fuel for it. That means less weight in the dinghy, less fuel to find a safe place for on the mothership, etc.

[more]

Originally Posted by Pepijn

I got prices and weights for new 2 and 4 strokes. Trying to decide based on pros and cons.

Our plans are cruising fulltime in the Med 23/24 and in the Carib 2025 and further perhaps.

We have a Moody 425 and a new Highfield CL290 (9’6) at 59kg. We got a 2:1 dinghy OB lift.

I got the following:
Merc 9.9hp 2str @ 1999euro (26kg)
Merc 15hp 2 str @ 2399.euro (41kg)
Honda 10hp 4 str @ 2580 euro (42kg)
Tohatsu 9.8hp 4 str @ 2480 euro (37kg)
Tohatsu 9.9hp 4 str @ 2854 euro (43kg)
Tohatsu 15hp 4 str @ 2998 euro (43kg)
Note: most 4 strokes are EFI’s.

Tohatsu 9.8hp 4 str @ 2000-2050 euro (37kg) Croatia,slowenia carb
Tohatsu 9.9hp 4 str @ 2854 euro (43kg) not on market for now
Tohatsu 15hp 4 str @ 2900 euro (43kg)
Tohatsu 20 suzuki 20 efi 3000-3200€
mercury efi 20 hp 3000-3100€

all price with tax

check here in slowenia https://jaanit.com/kategorija/navtik...max_price=3444

i always arrange 4-5% discount

[Adelie]

Originally Posted by MicHughV

picky..picky....ok...GE or Rolls engines...

and PRATT & Whitney and CFN.
And then there are the APUs which seem to mostly be Garrett and Honeywell.

[more]

Tohatsu Marine now produces 700 different types of outboard engines in one factory that are classified by detailed specifications. close 1000 outboard daily leave factory.

[merrydolphin]

I would DEFINITELY get the 2 stroke. Simpler, more dependable, lower maintenance and most of all, lighter! Especially with your requirements, a 15 is MUCH better. And on a small inflatable dingy a 4 stroke 15 has the transom of the dingy half submerged when sitting or going slow. No thats to that. 4’s are a nuisance to maintain and not as dependable and harder to work on. And out in mostly open waters where we cruise and anchor, I don’t think the 2 stroke issue is a problem like on a lake or something.

[more]

Originally Posted by merrydolphin

I would DEFINITELY get the 2 stroke. Simpler, more dependable, lower maintenance and most of all, lighter! Especially with your requirements, a 15 is MUCH better. And on a small inflatable dingy a 4 stroke 15 has the transom of the dingy half submerged when sitting or going slow. No thats to that. 4’s are a nuisance to maintain and not as dependable and harder to work on. And out in mostly open waters where we cruise and anchor, I don’t think the 2 stroke issue is a problem like on a lake or something.

pleas tell me how to buy new 2-stroke in USA or EU and dont break law.
i really wat buy new
yamaha enduro in EU,before be possible over fisherman now is closed this line.

[malbert73]

Originally Posted by merrydolphin

I would DEFINITELY get the 2 stroke. Simpler, more dependable, lower maintenance and most of all, lighter! Especially with your requirements, a 15 is MUCH better. And on a small inflatable dingy a 4 stroke 15 has the transom of the dingy half submerged when sitting or going slow. No thats to that. 4’s are a nuisance to maintain and not as dependable and harder to work on. And out in mostly open waters where we cruise and anchor, I don’t think the 2 stroke issue is a problem like on a lake or something.

Mostly a myth now, but was true with older 4 strokes. Weight difference has shrunk to 5-10 lbs in many cases. 4 stroke EFI is now the most reliable option out there. No carb to clean. Spend a bit of money and install a pre filter and water separator which is a good idea regardless.
And so quiet and smooth even idling.
As for environmental impact, yes a big difference yet small impact overall, but really there’s no reason not to go 4 stroke EFI at this point if you really dig into the facts

[sailingharry]

Originally Posted by malbert73

Mostly a myth now, but was true with older 4 strokes. Weight difference has shrunk to 5-10 lbs in many cases.

Not true. Our 2018 Tohatsu 9.8 2-stroke weighs 57.3 lbs. A Tohatsu 9.9 EFI 4-stroke weighs 94.7 lbs. Almost 40 lbs more! And already a bit of challenge lifting the dink by hand with the motor on (98% of the time, twice a day), and wrestling the motor on/off when needed. The Yamaha shaves 7 pounds off, for 87 pounds. The Honda is 103 lbs.

Our dink is rated for 10hp max, so getting 9.9 in a 20 hp frame is a bad combination.

Mixing oil adds 60 seconds to a fill-up, and we burn 10-20 gallons a year so it's hard to worry about environmental impact. And weird, but I don't see any oil on the water or smell a lot of exhaust.