I almost never buy gas at a boat gas dock. This carburetor problem is somewhat
recognized. It may be tied to gasahol. When gasahol was introduced to the NE
USA, the incidence of blocked carbs on 4 strokes went up dramatically. I have
talked to good mechanics here on Lake Michigan, and they show me 4 stroke
engines lined up waiting to have their carbs cleaned. The problem is in these
fine
jets they use. If you haven't had any problems, you are possibly the exception.

Sherwin D.

Charlie Morgan wrote:

On Fri, 23 Mar 2007 07:39:47 -0500, lid wrote:

Charlie Morgan wrote:
a 1992, which has had the carb cleaned TWICE
in 15 years

Do you have any tricks that haven't already been mentioned to keep
your jets from clogging during non-use?

Rick

I don't know. I use a filtered funnel (yes, I've observed particles
being caught in the filter!) when I fill the tank, and the inside of
the tank is clean and rust free. I inspect it each spring with a
dental mirror and a flashlight. I ALWAYS add Stabil to gas when I fill
up my jerry cans. I also buy my gas from a "land" gas station that
does a lot of business, so maybe their gas is fresher? I avoid getting
gas from gas docks whenever possible.

I'm somewhat suspicious of the fact that gas docks around here sit
idle all winter. That may lead to a lot of crap accumulating in their
storage tanks that then gets pumped into Sherwindu's boat. ;^)

CWM

My lawnmower mechanic warns me not to depend on Stabil for anything longer than
a month, or so. It too will loose it's protective abilities. I don't have any
problems
with my 4 stroke lawnmowers. It could be a factor that the outboards are out
there
in the sun where the gas gets heated up encouraging particulates to form. I
don't
think anyone has done a careful study of this, and the outboard people certainly
don't
want to reveal any defects in their design.

Sherwin D.

Charlie Morgan wrote:

On Fri, 23 Mar 2007 09:25:27 -0500, lid wrote:

Charlie Morgan wrote:
I ALWAYS add Stabil to gas when I fill
up my jerry cans.

I've been hearing about Stabil more and more. I've never needed or
used it until now. I've always just run my carbs dry when I get in. If
small jets are in my future though, guess I'd better stock up. Does
"Stabil" have any competition... any sort of generic stuff, lower
price, that can do the same thing?

Rick

I imagine there are other similar products, but Stabil is very well
known, and it works, so I haven't been tempted to try any others. A
little goes a long way, so I never considered the cost. I put it in
ALL of my small engines, including 2-stroke weed wackers, 4-stroke
lawn mowers, etc.

As far as the frequently repeated suggestion that 4-strokes have more
problems due to "smaller jets"... I would suspect that the jets on a
4.5 HP lawnmower would be a LOT smaller than the jets in a 9.9 HP
Yamaha outboard. I find the "smaller jets" theory to be nonsensical,
and without any basis in fact. Some people just aren't very careful
about keeping particulates and gum out of their fuel tanks. It really
doesn't take much effort.

CWM

lid wrote:

sherwindu wrote:
It remains to be seen just how
high (not low) a gear ratio they come up with.

You say to-may-to, I say to-mah-to. I'd say 4:1 is lower than 2.92:1.

My Seagull had a whopping 4 to 1ratio.

Yup, they don't make 'em like they used to. But wasn't it a much lower
horsepower engine? It would need all that leverage to push the same
load.

I remember advertising pictures of these larger Seagulls pushing heavily
laden
barges. True, it would take them time to get the vessels moving, but they
had
the torque to do the job. The only problems with the Seagulls were the
mixing
of the gas and oil, and the annoying noise and vibration. They were simple
to fix.
I even rebuilt the lower gear box on one going down the Mississippi, and I'm
not
an experienced mechanic.




No manufacturer has yet come close to that.

Not that I know of either. At least not at 9.9hp or above. Your T9.9
is 2.92:1. That's as low as I've seen currently. Mercury is 2:42:1 and
Honda is 2.33:1.

My Yamaha is about 100 pounds, so 96 pounds is no big deal.

Yamaha spec sheet shows 108. For me, 12lbs might be big enough to tip
the balance, all else being equal.

Actually, I looked up the weight in my 2002 Yamaha catalog and the T9.9
high thrust engine is listed as 99 pounds.



Rick

sherwindu schreef in


I almost never buy gas at a boat gas dock. This carburetor problem is
somewhat recognized. It may be tied to gasahol. When gasahol was
introduced to the NE USA, the incidence of blocked carbs on 4 strokes
went up dramatically. I have talked to good mechanics here on Lake
Michigan, and they show me 4 stroke engines lined up waiting to have
their carbs cleaned. The problem is in these fine
jets they use. If you haven't had any problems, you are possibly the
exception.

To be quite onest: I live in the Netherlands (Europe) and I have never ever
experienced anything like a blocked carburettor in the outboards I have
owned. At present I have a 6 hp Mercury four stroke outboard.
When I have delivered the boat at the yard where it is laid up for the
winter, I take the engine home, without having let the carbs run dry, and
put it in storage.
In spring I put it on the boat, connect it tot the fuel tank (often
containing 5 months old gasoline). The engine starts (with good priming) at
one or two pulls on the cord and runs perfect ever after.

Your problem must be something with the fuel you use.

--
Lodewijk

Lodewijk Stegman wrote:
Your problem must be something with the fuel you use.

Seems so.
In fact that's my mechanic's theory. His exact words were "the gas
we've been getting lately ain't worth crap". I'm not sure who he meant
by "we" but maybe he meant our part of the country. That'd make sense
if other parts of the world don't have the same problems.
I buy most of my gasoline at the Exxon station around the corner. They
do a high volume of sales and I doubt gas stays in their tanks very
long at all. But it does seem odd that some people have problems with
gummy carbs and other people don't.

Rick

lid wrote:

Lodewijk Stegman wrote:

Your problem must be something with the fuel you use.


Seems so.
In fact that's my mechanic's theory. His exact words were "the gas
we've been getting lately ain't worth crap". I'm not sure who he meant
by "we" but maybe he meant our part of the country. That'd make sense
if other parts of the world don't have the same problems.
I buy most of my gasoline at the Exxon station around the corner. They
do a high volume of sales and I doubt gas stays in their tanks very
long at all. But it does seem odd that some people have problems with
gummy carbs and other people don't.

Rick

Try mixing 5% low sulfur diesel into the fuel.

More power and less deposits on the carb. Don't exceed 5% though, or
you'll foul plugs.
It won't go bad as fast either.

--
“TAANSTAFL”

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"A prudent man foresees the difficulties ahead and prepares for them;
The simpleton goes blindly on and suffers the consequences." - Proverbs 22:3
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