2 Stroke can of worms - judge Judy

[Fenlander]

Ahh OK... as you can see from my profile I have the Tohatsu 9.8 2-stroke at the moment and I also owned a 2006 model around 2008.

A couple of years back I owned a new Mariner 9.8 4-stroke which you might be aware is the same basic engine as the Tohatsu.

So differences...

The 10-12kg weight saving of the 2-stroke is a game changer... so so easy to manage.

I've run both those OBs on the same SIB and the top speed was the same.

From cold they are both decent starters but the 2-stroke is a lighter pull and easier to manage from cold as you can put the choke in quite quickly but the 4-stroke needed warming up or it was inclined to stall when pulling away from the slip. Hot starting both fine.

Re noise the 4-stroke quieter at idle but the 2-stroke still not noisy. At speed they were little different in volume but with the 2-stroke being a bit more buzzy.

Re vibration if anything the 2-stroke is better but not a lot in it.

Fuel usage was about 1lit an hour greater with the 2-stroke at near max revs... in truth negligible in the costs of running. Both had a decent range on the standard 12l tank... perhaps take a spare 5l can on longer days out.

Servicing more onerous on the 4-stroke with engine oil changes, valve clearances and a timing belt change around 4yrs over and above the needs of the 2-stroke.

Reliability should be good for both but less to go wrong on the 2-stroke.

[Notebook]

Thanks ever so much for your reply.

[Fenlander]

>>>Ok. So nobody uses one here that was bought second hand?

There are quite a few folks on here with pre legislation 2006/7 models they have bought used. There are also quite a few who have post legislation models bought new or used in different circumstances.

No need to keep pushing folks into a corner as to what they have done to get their holy grail 2-stroke. If you want one just do what you feel happy with and what leaves you at peace with your god.

[Pikey Dave]

Originally Posted by Fenlander

>>>Ok. So nobody uses one here that was bought second hand?

No need to keep pushing folks into a corner as to what they have done to get their holy grail 2-stroke. If you want one just do what you feel happy with and what leaves you at peace with your god.

Small Ribber is back.

[Notebook]

Originally Posted by Fenlander

>>>Ok. So nobody uses one here that was bought second hand?

There are quite a few folks on here with pre legislation 2006/7 models they have bought used. There are also quite a few who have post legislation models bought new or used in different circumstances.

No need to keep pushing folks into a corner as to what they have done to get their holy grail 2-stroke. If you want one just do what you feel happy with and what leaves you at peace with your god.

Perhaps I am asking the wrong questions
Ok so I buy one outside the eu. Pay all my taxes.
Place it on my boat.
Can I get pulled for having it I guess I am asking.
Like driving with no mot, tax seatbelt on a car?
As for the latter, I recycle everything.
Just so happens all my plastic comes from supermarkets who cleverly have placed this at our feet.
There is a scale of 1-10 on recyclable items in some countries. People sort them into these. However only 2 are recyclable. It’s a story for children with the rest.
Thanks again for your reply

[Blankton]

Originally Posted by Fenlander

Ahh OK... as you can see from my profile I have the Tohatsu 9.8 2-stroke at the moment and I also owned a 2006 model around 2008.

A couple of years back I owned a new Mariner 9.8 4-stroke which you might be aware is the same basic engine as the Tohatsu.

So differences...

The 10-12kg weight saving of the 2-stroke is a game changer... so so easy to manage.

I've run both those OBs on the same SIB and the top speed was the same.

From cold they are both decent starters but the 2-stroke is a lighter pull and easier to manage from cold as you can put the choke in quite quickly but the 4-stroke needed warming up or it was inclined to stall when pulling away from the slip. Hot starting both fine.

Re noise the 4-stroke quieter at idle but the 2-stroke still not noisy. At speed they were little different in volume but with the 2-stroke being a bit more buzzy.

Re vibration if anything the 2-stroke is better but not a lot in it.

Fuel usage was about 1lit an hour greater with the 2-stroke at near max revs... in truth negligible in the costs of running. Both had a decent range on the standard 12l tank... perhaps take a spare 5l can on longer days out.

Servicing more onerous on the 4-stroke with engine oil changes, valve clearances and a timing belt change around 4yrs over and above the needs of the 2-stroke.

Reliability should be good for both but less to go wrong on the 2-stroke.

Spot on write up. I've had 15hp Yamaha in both flavours, the common criticisms levelled at 2 strokes - smokey, noisy, inefficient - are negligible in my opinion. Maybe a 40 year old evinrude that's gone through 10 owners might be those things, but a decent one will run well.

The 2 stroke has a different pitch, but I don't think it's noisier. I think my fuel consumption probably decreased slightly, owing to easier planing with a lighter engine.

[Blankton]

Originally Posted by Notebook

Perhaps I am asking the wrong questions
Ok so I buy one outside the eu. Pay all my taxes.
Place it on my boat.
Can I get pulled for having it I guess I am asking.
Like driving with no mot, tax seatbelt on a car?
As for the latter, I recycle everything.
Just so happens all my plastic comes from supermarkets who cleverly have placed this at our feet.
There is a scale of 1-10 on recyclable items in some countries. People sort them into these. However only 2 are recyclable. It’s a story for children with the rest.
Thanks again for your reply

No. Your fine. In fact the ex rnli 2 strokes get sold off to the general public. So you can buy a post 2006 engine legally for leisure use, so long as its not new. No-one would be in the slightest bit interested, but even if they were, just say you brought it secondhand.

[Limecc]

Originally Posted by Pikey Dave

Small Ribber is back.

Called it
Not entirely convinced though

[Notebook]

Originally Posted by Blankton

No. Your fine. In fact the ex rnli 2 strokes get sold off to the general public. So you can buy a post 2006 engine legally for leisure use, so long as its not new. No-one would be in the slightest bit interested, but even if they were, just say you brought it secondhand.

Thanks

[The Gurnard]

I must admit..after reading some replies on here, I though my 2006 Mariner two stroke was knackered ..and so were the other two guys 25HP two strokes that I know ..simply because I need almost twice as much fuel as people like Jeff does with his 25HP EFI four stroke..its very obvious its much noisier ..and it reeks of two stroke especially cold starting in a bucket to flush it out.

But then I read some other websites views from manufacturers?

Just a quick sample of quotes

“From a cost perspective, a 4-stroke outboard is far more fuel efficient than a 2-stroke. The fuel efficiency of a 4-stroke motor can be 50% better than that of a 2-stroke motor with the same HP.”

“Older 2-stroke motors that rely on carburetors are particularly bad for emissions and fuel economy.”

The first thing to keep in mind is that both 4-stroke and direct injection 2-stroke outboards on average are more than 35 percent better than traditional carbureted 2-strokes on fuel consumption, according to Tom Mielke, outboard marketing director for Mercury Marine. That percentage is based on how an average boater would use an outboard, he says.

They’re quieter than 2-strokes, with the lower pitch of the motor being less of a nuisance.

2-strokes are generally louder than 4-strokes, and the higher pitch of the 2-stroke’s engine can make it unpleasant to hear.

So now I have a more balanced view..Im happy that my 25HP two stroke is noiser..very much thirstier and smelly. And that it is not knackered yet.

[Notebook]

Originally Posted by The Gurnard

I must admit..after reading some replies on here, I though my 2006 Mariner two stroke was knackered ..and so were the other two guys 25HP two strokes that I know ..simply because I need almost twice as much fuel as people like Jeff does with his 25HP EFI four stroke..its very obvious its much noisier ..and it reeks of two stroke especially cold starting in a bucket to flush it out.

But then I read some other websites views from manufacturers?

Just a quick sample of quotes

“From a cost perspective, a 4-stroke outboard is far more fuel efficient than a 2-stroke. The fuel efficiency of a 4-stroke motor can be 50% better than that of a 2-stroke motor with the same HP.”

“Older 2-stroke motors that rely on carburetors are particularly bad for emissions and fuel economy.”

The first thing to keep in mind is that both 4-stroke and direct injection 2-stroke outboards on average are more than 35 percent better than traditional carbureted 2-strokes on fuel consumption, according to Tom Mielke, outboard marketing director for Mercury Marine. That percentage is based on how an average boater would use an outboard, he says.

They’re quieter than 2-strokes, with the lower pitch of the motor being less of a nuisance.

2-strokes are generally louder than 4-strokes, and the higher pitch of the 2-stroke’s engine can make it unpleasant to hear.

So now I have a more balanced view..Im happy that my 25HP two stroke is noiser..very much thirstier and smelly. And that it is not knackered yet.

Brilliant

[The Gurnard]

Its just my opinion Notebook. but anyone who wants to swap a decent 25 HP four stroke for my 25HP Two stroke is more than welcome.. In my experience ..there is a very noticeable difference

Just checked some figures..Jeff and Myself did the exact same trip in July , same speeds and distance ..His 25HP Suzi EFI used 35 litres. My 25HP two stroke used 57 Litres plus 0.5 litre oil

Estimated Jeff cost at £1.35p per litre £47 my cost £82 which for me is quite a significant amount of money for one trip. The weight of extra fuel I have to carry for a decent day out is far more than the difference in weight of a 4 stroke compared to a two stroke.

When Im running my 25HP two stroke..I don’t bother switching on my handheld VHF as I cant hear a thing above the buzz. I do hear it and have it switched on when Im in a 25HP four stroke boat.


My neighbours when I lived in the city complained when I flushed the two stroke out in a bucket at home as the reek filled their rooms if their window was open.. I could understand it as I had to close all my windows. they never complained about the four stroke getting flushed and I didnt bother closing windows.

[Notebook]

Originally Posted by The Gurnard

Its just my opinion Notebook. but anyone who wants to swap a decent 25 HP four stroke for my 25HP Two stroke is more than welcome.. In my experience ..there is a very noticeable difference

Just checked some figures..Jeff and Myself did the exact same trip in July , same speeds and distance ..His 25HP Suzi EFI used 35 litres. My 25HP two stroke used 57 Litres plus 0.5 litre oil

Estimated Jeff cost at £1.35p per litre £47 my cost £82 which for me is quite a significant amount of money for one trip. The weight of extra fuel I have to carry for a decent day out is far more than the difference in weight of a 4 stroke compared to a two stroke.

When Im running my 25HP two stroke..I don’t bother switching on my handheld VHF as I cant hear a thing above the buzz. I do hear it and have it switched on when Im in a 25HP four stroke boat.


My neighbours when I lived in the city complained when I flushed the two stroke out in a bucket at home as the reek filled their rooms if their window was open.. I could understand it as I had to close all my windows. they never complained about the four stroke getting flushed and I didnt bother closing windows.

The more I think about it, first boat, cost of importing etc might just get a 4 stroke 6hp and see how it goes. I’m a bit of a James may when it comes to driving, never over the speed limit etc.
Possibly change the prop for a tad more grunt.
That’s anther episode.
Thanks

[The Gurnard]

Originally Posted by Notebook

4 stroke 6hp and see how it goes.
Thanks

The last outboard I needed..thats exactly what I did...and it saves all sorts of issues. and will have a warranty you can use if you buy new from a dealer

Whichever brand you buy..best get one that can be laid on three sides. My Yamaha 6HP can and never had an issue throwing it in the car..as long as its not upside down.

No cam belt to worry about and tappets are real easy..a few seconds and they are done..they only need checked every three years according to the manual..but its that easy..I check them every service anyhoo.

Enjoy your setup

[Fenlander]

I always rate for a general guide the fuel consumption charts Tohatsu publish. Interestingly they show the 25% extra usage for a 2-stroke at the 10hp size widening to an extra 50% at the 25hp size. Broadly in line with your experience vs Jeff.

There is no doubt the current 2-stroke popularity in the portable sizes is all about weight where you can have 50-66% more power for the same weight as a 4-stroke. Of course this advantage fades as you get to 25hp motors on trailed outfits.

[Notebook]

Originally Posted by The Gurnard

The last outboard I needed..thats exactly what I did...and it saves all sorts of issues. and will have a warranty you can use if you buy new from a dealer

Whichever brand you buy..best get one that can be laid on three sides. My Yamaha 6HP can and never had an issue throwing it in the car..as long as its not upside down.

No cam belt to worry about and tappets are real easy..a few seconds and they are done..they only need checked every three years according to the manual..but its that easy..I check them every service anyhoo.

Enjoy your setup

The tohatsu 6 4 stroke can be on 3 sides.
Thanks

[jeffstevens763@g]

Small ribber asked the same question last year I did check the search function does work for info

[The Gurnard]

Originally Posted by Fenlander

Of course this advantage fades as you get to 25hp motors on trailed outfits.

Hi Fenlander To confuse the can of worms even more .. I will add ..a 20HP old school two stroke is around 47-50 KG ..

I got that info from the link below

https://www.rib.net/forum/f50/weight...ard-37030.html

Yet a new 20HP Four stroke EFI Suzuki is around 44kg ..so is in fact lighter than the older 20 HP two strokes. I suspect 20HP is the most popular size for a family size SIB .. so worth noting even the weight advantage is gone for 20HP ?

[Searider]

Originally Posted by Notebook

Thanks
Ok. So nobody uses one here that was bought second hand?
Thanks for your reply

If it was manufactured after 2006 you shouldn't. I'm sure there are some later ones in circulation though. I doubt Trading Standards have the resources to police it however......

[TmMorris]

Originally Posted by Fenlander

I always rate for a general guide the fuel consumption charts Tohatsu publish. Interestingly they show the 25% extra usage for a 2-stroke at the 10hp size widening to an extra 50% at the 25hp size. Broadly in line with your experience vs Jeff.

There is no doubt the current 2-stroke popularity in the portable sizes is all about weight where you can have 50-66% more power for the same weight as a 4-stroke. Of course this advantage fades as you get to 25hp motors on trailed outfits.

I think that to get those kind of differentials a lot of that data is carb v FI in reality. For a 2 stroke to be half as efficient as a 4 pot it's impossible to think the same fuelling systems are being compared.

If both are on EFI you'd expect around a 20% gain with a 4 stroke.

It's always surprised me how the weight advantage of the 2 strokes seems to evaporate almost entirely at the 20hp level and at that level and beyond it basically becomes a smellier, dirtier, noisier, less efficient means to save a bit on the front end.