Poke A Stick In A Hornets Nest Or Start A Oil Thread

DECK SWABBER 58

Lieutenant Commander
Joined
Aug 14, 2009
Messages
1,913
I'm totally confused.:confused::

I've spent time searching the "oil" threads here. Holy smokes, what entertainment.:D

My dilemma:
I have a 2008 Tohatsu 9.8 four stroke that I bought last year with
5 hrs on it. It now has approx. 20 hrs. on it. I did the 1st oil change
at 10 hrs and then another at the end of the season. I'm using napa
(valvoline) 10-40 automotive oil.

Since I'm 52 and assuming Tohatsu quality this motor will last my
lifetime. Since it's now broken in and I will not be putting more
then 50 hrs. a season on it I was thinking of switching to a synthetic
for insurance purpose's.

:eek::eek::
T.G. says no no no. The 4 stroke runs too cool already and syn. oil
just adds to the making oil problem.
My Tohatsu dealer says what I'm using is just fine but.... mobil 1
is what a lot of customers are using. Mobil 1 does not make a 10-40
which Tohatsu recommends above 86 deg., which will happen here.
Mobil 1 and Napa oils are not 4C-W rated. Amsoil makes a 10-40
4C-W rated synthetic. And of course their are plenty of 4C-W
non-synthetic's.

So.........should I just keep using the automotive oil that I'm using
or switch to a 4C-W non-synthetic or go to a 4C-W synthetic?

Cost is not an issue, it holds 1qt. and I'm going to change it once
a year.

I fear that I have started the hampster wheel a'spinnin. Hopefully
not.:)

JB, sorry in advance, but poking the stick in the hornet's nest is
good for my old heart. It help get's the adrenaline pumping.:D
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Poke A Stick In A Hornets Nest Or Start A Oil Thread

Here is my suggestion on any oil thread.
1. Use what is recommended by the manufacturer. They normally have a couple of choices.
2. if you do not choose to use what the manufacturer suggests, then use whatever you want. Doesn't even matter where you get it or anything else. It's not what the manufacturer suggests.
Then go boating. No matter what oil it is, someone, somewhere, someplace, thinks it's the best thing since sliced bread, and would recommend it in anything, lawnmower, airplane, boat, you name it.
And, if the thread lasts long enough there will be a few more agree to it.

What it amounts to is if you choose an oil and change it yearly with low hours, it will work fine. I have never seen a 4 stroke engiine fail because of the type oil used on a low hour engine with frequent oil changes.
 

DECK SWABBER 58

Lieutenant Commander
Joined
Aug 14, 2009
Messages
1,913
Re: Poke A Stick In A Hornets Nest Or Start A Oil Thread

Here is my suggestion on any oil thread.
1. Use what is recommended by the manufacturer. They normally have a couple of choices.
2. if you do not choose to use what the manufacturer suggests, then use whatever you want. Doesn't even matter where you get it or anything else. It's not what the manufacturer suggests.
Then go boating. No matter what oil it is, someone, somewhere, someplace, thinks it's the best thing since sliced bread, and would recommend it in anything, lawnmower, airplane, boat, you name it.
And, if the thread lasts long enough there will be a few more agree to it.

What it amounts to is if you choose an oil and change it yearly with low hours, it will work fine. I have never seen a 4 stroke engiine fail because of the type oil used on a low hour engine with frequent oil changes.
Thanks Don, your input is appreciated. Good advice.
In my owners manual Tohatsu does not even mention 4C-W oil.
 

itsaboattime

Senior Chief Petty Officer
Joined
Jul 4, 2007
Messages
791
Re: Poke A Stick In A Hornets Nest Or Start A Oil Thread

I have to believe that the manufacturer recommended oil is the best oil for the motor.
 

JET4

Cadet
Joined
Mar 7, 2010
Messages
23
Re: Poke A Stick In A Hornets Nest Or Start A Oil Thread

I just bought a Tohatsu 9.8 and I will be using Amsoil in it.
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,575
Re: Poke A Stick In A Hornets Nest Or Start A Oil Thread

As a dealer and Tohatsu tech who personally owns a 9.8A3 used on the Great Lakes, I can offer this:

Any 4-stroke will be more prone to oil dilution and "making oil" under conditions that promote blow-by. This includes: 1- cold running, 2- lots of idling, 3- overfilled (even slightly) crankcase, 4- synthetic oils, 5- incomplete break-in, 6- not achieving correct WOT regularly.

Now consider this: The 9.8 cools very well -- almost too well. Northern freshwater is typically cold all the time. Many 9.8s are idled a lot for trolling. The 9.8 crankcase holds a pint and a half, but some owners overfill it by dumping in a whole quart. Many 9.8s never get run hard enough for proper ring seating. Many 9.8s are a bit over propped, so they don't ever reach WOT.

So... If you are correctly propped (approx. 6,000 RPM at WOT), did a superb break-in, run in warm water, and run it hard, synthetic may be OK. You won't benefit from extended oil changes, however. Since the 9.8 does not have an oil filter, changes are the only way crud gets removed from the crankcase. Since it uses so little oil, cost of the oil isn't a factor. Ditto for fuel economy. As for wear, we see more wear issues from improper/inadequate winterizing than from hours of use.

OK, I'm getting down from the soap box.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Poke A Stick In A Hornets Nest Or Start A Oil Thread

I agree completely with Don S.
 

TOHATSU GURU

Admiral
Joined
Jul 22, 2004
Messages
6,164
Re: Poke A Stick In A Hornets Nest Or Start A Oil Thread

I agree with everyone about everything...As my head slams to my desk top because I just don't understand why people WANT to use synthetic in an outboard.
 

DECK SWABBER 58

Lieutenant Commander
Joined
Aug 14, 2009
Messages
1,913
Re: Poke A Stick In A Hornets Nest Or Start A Oil Thread

Thanks everyone for the replies. I'm going to stay with non-synthetic.

Paul or T.G., do you have any opinions on why the tohatsu manual does not
specify a FC-W oil ? Genuine tohatsu oil is FC-W, when I asked my
dealer who I trust he said why spend the money, just use a good
10-40 motor oil. I think a few extra dollars is worth it for the FC-W.

Tohatsu Guru I hope you did not injure yourself.:D

Jet4 welcome aboard. Their is a incredible amount of knowledge and experience here. Take advantage of it.:rolleyes:
 

TOHATSU GURU

Admiral
Joined
Jul 22, 2004
Messages
6,164
Re: Poke A Stick In A Hornets Nest Or Start A Oil Thread

Luckily there is no drain bramage.

Depending on the last revision date of the manual it will specify the newer Fc-W oil....I would much rather someone run an auto 10w-30 than a Fc-W 10w-40.
 
Last edited:

DECK SWABBER 58

Lieutenant Commander
Joined
Aug 14, 2009
Messages
1,913
Re: Poke A Stick In A Hornets Nest Or Start A Oil Thread

Luckily there is no drain bramage.

Depending on the last revision date of the manual it will specify the newer Fc-W oil....I would much rather someone run an auto 10w-30 than a Fc-W 10w-40.
WHY???
 

TOHATSU GURU

Admiral
Joined
Jul 22, 2004
Messages
6,164
Re: Poke A Stick In A Hornets Nest Or Start A Oil Thread

Because 10w-40 is too heavy for most applications. Remember, what people need to do(in defiance of common sense) is to raise the engine's temperature. Consequently, 10w-30 will help to raise that engine temp another degree or two. Every little bit helps in that fight against dilution.
 

DECK SWABBER 58

Lieutenant Commander
Joined
Aug 14, 2009
Messages
1,913
Re: Poke A Stick In A Hornets Nest Or Start A Oil Thread

Because 10w-40 is too heavy for most applications. Remember, what people need to do(in defiance of common sense) is to raise the engine's temperature. Consequently, 10w-30 will help to raise that engine temp another degree or two. Every little bit helps in that fight against dilution.
THANKS, 10-30 FC-W it is.

While the manual shows 10-30 up to 86 deg. F and here it often goes into the 90's in july and august it sounds like a little bit of extra heat will be a good thing.

With all the good advice I've received here I'm now confident with reg.
maint. my little tohatsu will give me many years of reliable service.:)
Thanks again,
Brian
 
Top