9 year old Mariner 6hp, is a new Tohatsu 6hp better?

[graham2burton65@gmail.com]

Hi good folks,

I have inherited a well cared for 6hp Mariner. Circa 2011
I am tempted to sell it and buy a new Tohatsu 6hp.

safety .......newer means more reliable, maybe
comfort......newer means quieter, or does it?
front gear change looks useful, but is it?

I am most interested in the reduction of noise.

do any of you have a view on this from direct experience? Any other options?
I have seen the discussion about the new electric option, but have ruled this out as I intend to be places where charging is not an option.

thankfully I can afford to buy new if I wish.

proud new owner of Jaunty, a BC20
thanks
Graham B

[Julian Merson]

On my previous Drascombe, I replaced a 6hp Mariner with a new one of the same about four years ago.  Mercury, Mariner and Tohatsu are all basically the same engine with different lids.  I'd love to say it was quieter but it wasn't.  But it was certainly more reliable for being new.

The Yamaha 6 inherited on the BC20 is quieter at tickover but just as noisy at reasonable revs.  In fact, in the BC20 the noise is probably worse because the engine is closer. And confined to the cockpit well  I suppose it's all the more encouragement to sail rather than motor.  In my old boat I spent a day, in still winds, motoring across The Wash from Wells to The Humber.  I'm not sure I could do the same in the new boat - or, at least, I'd need a decent pair of ear plugs!

Probably not what you wanted to know, but that’s my experience.

[Graham W]

safety .......newer means more reliable, maybe
comfort......newer means quieter, or does it?
front gear change looks useful, but is it?

I am most interested in the reduction of noise

Safety - reliability depends on the amount of use (more, counter-intuitively = better) and management of fuel and in particular the effects on the engine of ethanol.  I know I sound like a cracked record but if you don’t use the engine much, your safest route is to avoid supermarket petrol altogether.  The extra expense on ethanol-free fuel is really, really worth it.

Comfort - I notice that Mariner claim the newest iteration of the 6HP benefits from “improved top cowl sealing and locking system for reduced sound emissions and improved sealing capabilities”.  On my old Mariner 6HP, vibration noise from the cowling was seriously annoying until I put an extra seal all away around the part where the engine meets the cowling, which improved it quite a lot.  Elsewhere on the forum, there has been a discussion of how to reduce the reverberation noise caused by having the outboard in a small enclosed space, the principal opening of which is right next to the helmsman’s ear.  Alternatively, find ways of sitting further forward when motoring, away from the outboard - throttle and tiller extensions can help.

Front gear change - much better when manoeuvring in tight spaces than having to fish about down the side of the engine, especially if you are sitting on the wrong side.

I agree wholeheartedly on noise, one of the reasons why I have swapped a reasonably quiet but slightly whiny Torqeedo for an almost silent ePropulsion.  Better range and robustness are other reasons for the swap.

[Sea Simon]

Reliability. I'm with GW. Aspen fuel seems to be key! Supermarket fuel worst, and it seems (lots of info on here) about to get worse again.
my new gen Honda 5 has been far better than the 3 year old Tohatsu on my Lugger. Web says Honda is a new gen engine, rather than an older engine modified to meet stricter Env standards.

I'm not against Tohatsu generally, have had several over the years on other boats, all OK. My last seemed to be a dud.
Three brands are the same engine, certainly at this size.. Mercury used to be "premium", Tohatsu "budget", Mariner "semi-commercial". I hear Mercury warranty is better?

To me, it came down to local dealers/service support on a new engine. Yamaha/Suzuki not considered, for that reason alone.
I got my Honda locally, yet at a very competitive price. Certainly feels better quality overall, tho now Chinese built too! My Tohatsu was Belgian.
Honda seems a little quieter, although boat layout v Drascombe Lugger, means the engine is closer.
On a long passage, I use my tiller extension and earplugs. Due to a lifetime around heavy machinery, I'm already a little deaf. A mixed blessing, confirmed by my wife's opinion too!

Disadvantage of Honda is that it still has a side gear lever. To me, not too bad really on a BR where engine is relatively accessible.
Remote fuel tank is a nice option to have. The new Honda now has both tanks.

Electric? Much discussion on here!
I borrowed a Torqueedo for a few days, and was very pleasantly surprised.
However, a "non-starter' ? for me, as most use is at sea in wind/tide. Charging was (say, after a coastal passage, non marina) a severe restriction on my options.
Also, have never been an "early adopter", as an professional  Engineer have witnessed too many technical disasters, and resulting fallout.... financial and personnel too.

[Julian Merson]

I'm no expert but have heard anecdotally of people having difficulty with Aspen fuel in outboards.  Interesting that it is so highly regarded here.
My approach is fresh, non-supermarket fuel for each trip, run the outboard dry at the end and empty remaining fuel, next day, in the Fiesta sat on the drive.  It seems to work.

[Graham W]

Web says Honda is a new gen engine, rather than an older engine modified to meet stricter Env standards.

That seems to be a key point if you’ve had outboard carburettor problems.  Some outboard manufacturers have taken quite old designs and crippled them to make them environmentally friendly.  I’m thinking particularly of the Suzuki 2.5HP which installed metal bits to stop you from changing the tuning of the engine, which would in turn have allowed you to reverse their modifications but at the cost of increased pollution.

[Graham W]

I'm no expert but have heard anecdotally of people having difficulty with Aspen fuel in outboards.  Interesting that it is so highly regarded here.
My approach is fresh, non-supermarket fuel for each trip, run the outboard dry at the end and empty remaining fuel, next day, in the Fiesta sat on the drive.  It seems to work.

Julian,

Not everyone, and especially me, can be bothered or in some cases is able to be as diligent as you in pursuing fuel hygiene routines. So it suits the lifestyle and avoids the resulting risks and repair cost from when the chickens come home to roost.  I’ve googled ‘Aspen fuel problems’ and couldn’t find anything much of substance.  The possibility was mentioned that Aspen may dislodge past problems caused by using supermarket unleaded, such as bits from the rubber fuel line assembly and varnish from elsewhere.  I’d be interested to know what your anecdotes said.

The biggest problem is to the wallet - the price of unleaded has fallen substantially but Aspen hasn’t fallen at all and is now nearly 4x the price.  However, if you’ve spent £1,000 on an engine and use 25 litres of Aspen a year (much less in my case), the £100 annual fuel cost seems to me to be a price worth paying.

[garethrow]

Does an engine need to be re-tuned to run on Aspen? I seem to recall reading somewhere that this is necessary but am not sure.

Gareth Rowlands
ex Gwennol Teifi S17
Soon to be Halen Y mor BR20

[Sea Simon]

Web says Honda is a new gen engine, rather than an older engine modified to meet stricter Env standards.

That seems to be a key point if you’ve had outboard carburettor problems.  Some outboard manufacturers have taken quite old designs and crippled them to make them environmentally friendly.  I’m thinking particularly of the Suzuki 2.5HP which installed metal bits to stop you from changing the tuning of the engine, which would in turn have allowed you to reverse their modifications but at the cost of increased pollution.

New-gen Honda as a major factor for me.
As per most small engines, the choice of 4/5/6 HP is down to carbs/jetting....and the HP "tax" of course! I seem to recall only the 6 can be had with a charge coil?
All can have sail drive props, for about £40 extra option. My dealer gave me the original, as a spare.

[Sea Simon]

Does an engine need to be re-tuned to run on Aspen? I seem to recall reading somewhere that this is necessary but am not sure.
Gareth Rowlands
ex Gwennol Teifi S17
Soon to be Halen Y mor BR20

No.

[Sea Simon]

My approach is fresh, non-supermarket fuel for each trip, run the outboard dry at the end and empty remaining fuel, next day, in the Fiesta sat on the drive.  It seems to work.

Julian,
Not everyone, and especially me, can be bothered or in some cases is able to be as diligent as you in pursuing fuel hygiene routines. So it suits the lifestyle and avoids the resulting risks and repair cost from when the chickens come home to roost. ..
The biggest problem is to the wallet - the price of unleaded has fallen substantially but Aspen hasn’t fallen at all and is now nearly 4x the price.  However, if you’ve spent £1,000 on an engine and use 25 litres of Aspen a year (much less in my case), the £100 annual fuel cost seems to me to be a price worth paying.

Agree with GW on both counts!

Fuel hygiene has to be a bit of a lifestyle thing?
I'm lucky, my boat is moored close to home, so short 1-2 hour trips are easy. In fact, I sailed in the river for a couple of hours over high tide last evening.
While your hygiene methods will do the job, essentially ... it's too much faff for me. However, i do run my engine on fresh supermarket fuel for longer trips. Then drying the carb seems to help too?
If I have to leave supermarket fuel in the engine, I keep a bottle of fuel stabiliser onboard.

I too have been wondering why Aspen prices have not moved!

Seems to be expensive, or a faff, or both?
I suppose it will drive even me into the arms of EProp eventually!

Still plenty of folks here using ex WD British Seagulls!

[Sea Simon]

So, to go back to OP....

If you can get a good deal (either selling or pxing) Mariner>Tohatsu (or other new motor) I'd swap asap.

There are some bargains, and hungry dealers about atm.

[Graham W]

Does an engine need to be re-tuned to run on Aspen? I seem to recall reading somewhere that this is necessary but am not sure.

Gareth Rowlands
ex Gwennol Teifi S17
Soon to be Halen Y mor BR20

I think I might be responsible for the idea that you might need to retune.  I sent my malfunctioning unleaded-fueled Mariner to the chap in Cheshire that Matthew and I have both used.  I asked him to clean out the carburettor (again) and after that, use a bottle of Aspen that I gave him and make sure that the engine would run sweetly on that. And it has, ever since!  I don’t know whether he actually had to retune or just had to clean out the gunk (again).  Given Simon’s reply, probably just the latter.

[Graham W]

Fuel hygiene has to be a bit of a lifestyle thing?

If you use the internal tank on the Mariner, as I have done quite often, it’s way too much of a faff to get the surplus fuel out of the tank each time after use.  Use a jiggle syphon?  Turn the engine upside down into a funnel?  Run it for an hour in the hope that all the fuel is used up?

On the other hand, if you’re using an external tank then fuel hygiene is a lifestyle thing.

[MarkDarley]

My Yamaha 6 has been incredibly reliable (watch it fail to start next time). At revs it is noisy but powerful.  I have ordered the Epropulsion for regular use, but will probably keep the Yamaha for the longer coastal trips.
I have never run the Yamaha on exotic fuels but I do always run the carburetor dry when finished.
I am not sure how relevant it is, but I will vouch for the Aspen fuel in my chainsaw.  I fired it up today after a 10 month lull, and it ran beautifully.  The foresters I know all use Aspen or have electric chain saws!

Mark
Wooden BR 20 "Pippin"