I have been having a series of problems with my 2002 Yamaha 9.9 4-stroke
outboard, mainly with blocked up carburetor jets. This season, I have had to
strip them down three times to clean the jets. I have been putting Stabil and
Mercury Quick Silver Cleaner in the gas tank, and that seemed to help for a
month, until today, while out on Lake Michigan the engine stopped running
again. I don't know if all 4-stroke engines behave like this, all Yamahas, or
just my particular engine. I expect better performance from an engine costing
over two thousand dollars.

"sherwindu" wrote in message
...
I have been having a series of problems with my 2002 Yamaha 9.9 4-stroke
outboard, mainly with blocked up carburetor jets. This season, I have had
to
strip them down three times to clean the jets. I have been putting Stabil
and
Mercury Quick Silver Cleaner in the gas tank, and that seemed to help for
a
month, until today, while out on Lake Michigan the engine stopped running
again. I don't know if all 4-stroke engines behave like this, all
Yamahas, or
just my particular engine. I expect better performance from an engine
costing
over two thousand dollars.




My 2002 T-8 has not had this problem. But I run a Racor or Sierra filter in
the feed line from the tank.

I also have an inline filter from the tank, plus the filter built into the
Yamaha. I don't
know if this is a factor, but my tank was very low on gas, about 1/8 full, but I
could
see there was gas in the window of my inline filter, and the squeeze bulb was
firm.
The engine only has about 30 hours on it, so I don't suspect the fuel pump. I'm
going
to replace the gas in the tank any ways, but I think the problem is that somehow
very
fine particles are getting through and clogging up the jets. I wonder though
about the
gas itself. What could happen to that to possibly cause the engine not to run,
considering that I had Stabil, Sea Foam, and Mercury Quick Clean in it? There
seems to be controversy in another thread about the lasting effects of Stabil.
My lawn mower mechanic says it won't last over a month. If changing the gas
does not
fix the problem, I will probably have to clean the carb jets again. I really
need a more permanent solution, so I can be confident about taking my boat on
longer
cruises.

Sherwin D.

CalifBill wrote:

"sherwindu" wrote in message
...
I have been having a series of problems with my 2002 Yamaha 9.9 4-stroke
outboard, mainly with blocked up carburetor jets. This season, I have had
to
strip them down three times to clean the jets. I have been putting Stabil
and
Mercury Quick Silver Cleaner in the gas tank, and that seemed to help for
a
month, until today, while out on Lake Michigan the engine stopped running
again. I don't know if all 4-stroke engines behave like this, all
Yamahas, or
just my particular engine. I expect better performance from an engine
costing
over two thousand dollars.




My 2002 T-8 has not had this problem. But I run a Racor or Sierra filter in
the feed line from the tank.

I find it useful to run my smaller gasoline engines out of gas if they
may sit for a while. Turn the gas off and let it run till it quits.
That lessens the fuel in the carb and reduces the deposites left by
that fuel evaporating. It does make it more work to start again though
as the fuel system has to fill up.

sherwindu wrote:
I also have an inline filter from the tank, plus the filter built into the
Yamaha. I don't
know if this is a factor, but my tank was very low on gas, about 1/8 full, but I
could
see there was gas in the window of my inline filter, and the squeeze bulb was
firm.
The engine only has about 30 hours on it, so I don't suspect the fuel pump. I'm
going
to replace the gas in the tank any ways, but I think the problem is that somehow
very
fine particles are getting through and clogging up the jets. I wonder though
about the
gas itself. What could happen to that to possibly cause the engine not to run,
considering that I had Stabil, Sea Foam, and Mercury Quick Clean in it? There
seems to be controversy in another thread about the lasting effects of Stabil.
My lawn mower mechanic says it won't last over a month. If changing the gas
does not
fix the problem, I will probably have to clean the carb jets again. I really
need a more permanent solution, so I can be confident about taking my boat on
longer
cruises.

Sherwin D.

CalifBill wrote:

"sherwindu" wrote in message
...
I have been having a series of problems with my 2002 Yamaha 9.9 4-stroke
outboard, mainly with blocked up carburetor jets. This season, I have had
to
strip them down three times to clean the jets. I have been putting Stabil
and
Mercury Quick Silver Cleaner in the gas tank, and that seemed to help for
a
month, until today, while out on Lake Michigan the engine stopped running
again. I don't know if all 4-stroke engines behave like this, all
Yamahas, or
just my particular engine. I expect better performance from an engine
costing
over two thousand dollars.




My 2002 T-8 has not had this problem. But I run a Racor or Sierra filter in
the feed line from the tank.

the price of the engine has nothing to do if you got plugged carb jets. You
need to figure out where the issue is... such as dirty fuel, gas tank,
hoses, etc. Why not have a marine dealer check it out?

"sherwindu" wrote in message
...
I have been having a series of problems with my 2002 Yamaha 9.9 4-stroke
outboard, mainly with blocked up carburetor jets. This season, I have had
to
strip them down three times to clean the jets. I have been putting Stabil
and
Mercury Quick Silver Cleaner in the gas tank, and that seemed to help for
a
month, until today, while out on Lake Michigan the engine stopped running
again. I don't know if all 4-stroke engines behave like this, all
Yamahas, or
just my particular engine. I expect better performance from an engine
costing
over two thousand dollars.

Here is the latest update on my problem. I cleaned out my tank and replaced it
with
fresh gas. I also purged the fuel delivery lines and the carburetor of old gas.
That did not do the trick to start the engine. There were some orangish deposits
on the
base of the carb after I opened it up. Also, some dark droplets were mixed in
with
the old gas taken out of the carb. What finally did the job was running fine
wires
through the low and high speed jets. It is working fine now, but for how long? I
think I might replace the fuel line for next year. I have been told I should be
using
at least a 10 micron filter. My external Tempo filter is only 40 microns. I have
no
idea what the filter inside the engine is rated for. The basic problem are these
very
fine jets on the smaller horsepower ( 9.9) four stroke engines. Yamaha has been
making them for some time, but seem to be burying the problem.

Sherwin D.

sherwindu wrote:

I have been having a series of problems with my 2002 Yamaha 9.9 4-stroke
outboard, mainly with blocked up carburetor jets. This season, I have had to
strip them down three times to clean the jets. I have been putting Stabil and
Mercury Quick Silver Cleaner in the gas tank, and that seemed to help for a
month, until today, while out on Lake Michigan the engine stopped running
again. I don't know if all 4-stroke engines behave like this, all Yamahas, or
just my particular engine. I expect better performance from an engine costing
over two thousand dollars.