sherwindu wrote:

Took my Yamaha 9.9 4 stroke out of storage (after 2 years) and tried to start it today. It would
not catch until I sprayed in some starting fluid, but then it would only rev up a bit and then
die. I think it is getting sufficient fuel from a supply tank, but that is one thing to check.
snip Sherwin D.

Sherwin,

I went through a similar problem with the Yamaha 9.9 4-stroke on my Catalina 27
earlier this year. BTW, I usually use gasoline squirted into the air intake on
the carburetor rather than starting fluid because the starting fluid
can be hard on the engine. I fill an oil squirt can with gas and apply a
couple of squirts into the air intake when I want to start it. Obviously be
careful with the raw gas, and don't get a fire started.

You can convince yourself that there's a problem with your fuel delivery by
keeping the motor running with carefully timed squirts of gas from your oil
can.

If the engine runs when you squirt in gas, and then dies when you quit, there is
a problem in your fuel delivery system somewhere. Did you pump the primer bulb
really well to make sure that fuel got all the way to the fuel pump? If so, it may be
that your fuel pump membrane has cracked, and is not pumping fuel to the carb. You can
check this by unclamping the fuel line that runs from the fuel pump (back of the
engine) to the carb at the fuel inlet barb on the carb, and cranking the engine.
If fuel comes gushing out, the pump is working, and the problem is with your carb.

If the problem is with the carburetor, it is likely that both the idle and main jet
are plugged with fuel debris. If either jet were clear, the engine would get enough
fuel mixed in the air to allow it to run although possibly not like it should.

Copy and paste the following link into your browser, and it will bring up an exploded
view and parts listing for the 1996 Yamaha 9.9HP 4-stroke carburetor.

http://www.boats.net/yamaha/partsyst...5dc715ee20c05c

You should be able to find a similar diagram and parts listing for _your_ carburetor on
this site as well. If you are mechanically inclined, you can take the carburetor off,
clean it out with lacquer thinner, unplug the jets, and reassemble it. If you are _really_
careful, you can do all of this and still use the original gaskets--I did ;-) You'll
need to use a small piece of wire to run through the jets to clean out the crap. These
are the parts labeled 8,9 (Main jet and nozzle), and 5 ("pilot" = idle jet) in the exploded
drawing. I use q-tips dipped in clean lacquer thinner for cleaning the inside of the
housings. Don't get the lacquer thinner on the plastic parts or the gaskets.


If you are not mechanically inclined, this is the time to get re-acquainted with your
favorite outboard mechanic and get ready to cough up some bucks. Note that a whole new
carb only costs $301.49 + shipping, so don't let the outboard shop gouge you for more than
that to rebuild your old one.

Good luck with it,

Don W.