New 4 stroke Outboard Compared To 90's 2 Stroke

[sigbear]

I had a 1994 2 stroke 8 HP mariner (bought new 1994) on my inflatable and that motor was a gem, always started right up and never had a problem for the 5 years I had it.

Just bought a brand new Tohatsu 8 HP 4 stroke and other than not having to mix oil/gas, what can I expect as far as performance, starting and reliability compared to the older 2 stroke engine?, pros and cons.

Sigbear

 

[JoeWhite]

I baught new 2004 Mercury 9.9 4-stroke for 6 years. In its advertisment it indicated that it would start on the first pull. I thought - yes ... will see. It alwasy started on the first pull. I never had any trouble. It had an electric starter as well - but I never used it. I gave it yearly tune - up that is 2 spark plugs and an engine oil change. I learned that you should always use up all the gas out of the carburator. So I always disconnected the fuel line and let the engine run until it ran out of fuel. This prevents gumming up of the carburator.

 

[Barnacle Bill]

4 strokes are quieter, more fuel efficient, smoke less and are heavier, but the Tohatsu/Nissan brands are the lightest of all the 4-strokes relatively speaking so sailors like them. I don't think anyone makes a 2 cycle outboard anymore because of EPA standards. You might find acceleration out of the hole is faster with a two cycle, but top end speed could be better, but that is only something dinghy use would care. On the back end of a sailboat that is not a concern.

 

[Terry in Naples]

Tohatsu 8 and 9.9

I bought a 9.9 a few months ago. (Tohatsu). It usually starts right up but I found you need to let it run a bit before taking off. Not doing that it stalls then is hard to start again. (automatic choke thingy) the weight is the same with both the 8 and the 9.9 so I went with the larger. I am having a lot of trouble adjusting to the 80# vs the old #60 of the 2 stroke. I can hardly muscle it around and taking it off the rail and handing it down to someone is impossible. Looks like it will remain on the dingy and on the davits for trips. Performance was great though and very quiet.

 

[bffatcat]

2 stroke vs 4 stroke

I had an 88 8hp 2 stroke mercury for many years and when it became unreliable in 08 I replaced it with a new 8hp 4 stroke tohatsu

Pros and cons of both

Both motors were reliable and started on the first or second pull
The Merc weighted about 70 lbs The Tohatsu weights 85 a plus for Merc
The Tohatsu ran quieter with more power and was less smoky A plus for the Tohatsu
The Tohatsu is much stingier on fuel than the Merc A Plus for the Tohatsu

And Finally The Merc ran fine on any kind of gas and you could leave it for the season with
no problems. The Tohatsu on the other hand does not like ethanol I have carry a minimum of gas so It dosent get old" no more than 30 days" and dump anything left in my
cars gas tank. I have tried to get airplane fuel in Ma but they will only sell it for planes
This is a major disadvantage.

 

[RichH]

bffatcat -

You can get non-ethanol adulterated marine gasoline in Mass. (and other states) at some marinas, etc. Valvtect is the 'brand'. I find that this stabilized, non-ethanolated, marine fuel will last over a year ... no need to run the carb dry every damn time.
Great for OBs with Tohatsu power-heads: Merc., Tohatsu, Honda, etc.

To find Valvtect dealers: http://www.valvtect.com/marina_search.asp

 

[Winkfish]

Check your owner's manual, too. I have a 1985 Merc, and it is OK to run up to 10% or 15% ethanol-gas in it. I try not to, but sometimes I don't have the option. No problems, knock on wood. I use the blue StaBil (formulated for ethanol gas) and Sea Foam at every fill-up.

 

[tommays]

All the new small outboards have the same E-10 issue as they all have to be tweaked to get the required 3 star rating

It was not much of and issue at 2 star but with 3 star any tiny piece of dirt stops up the idle circut

 

[wonkodsane]

It was not much of and issue at 2 star but with 3 star any tiny piece of dirt stops up the idle circut

My Merc 8HP's idle circuit looked like it had been plugged with amber. Was surprised not to find a well-preserved mosquito, a la Jurassic Park.

 

[Winkfish]

Wonk, now that you mention it, from the fishing/outboard forums I've seen here, it's not so much what the E-10 fuel does to the motor itself, but what it does to tanks, like fiberglass tanks and metal tanks with varnish on the inside. That, I believe, is what ends up gunking up the motors. My tanks are plastic, so I haven't had those issues.