I have an almost new Yamaha 9.9 high thrust outboard that is a real
pain to start - many pulls. Rummy's 8 Tohatsu fires up with one easy
pull. I don't know if it's the Yamaha or me, but it will take awhile
for this weekend's blisters to heal!
07 May 2000
I've got an older Yamaha 9.9 that gave me fits about starting until I
cleaned the carburetor. Seems that four cycle outboards are
sensitive to the carbs getting gummed up. I've heard of others who
have Honda's say much the same.
A suggestion I've been told is to run the carb dry (disconnect the
fuel hose and let the engine run out of gas) if your going to leave
the engine un-used for a long time.
I am assuming the Yamaha 9.9 TH,
in the gas I use: ring free(from the dealer), Marvel mystery oil,
gas stabilizer. all based on the rates on the side of the bottles/cans
I use two (sometimes 3 gas tanks) run the first one dry before
switching to the next to rotate the gas and not get a buildup of
old/new gas and the products I add.
Each time I leave the motor for overnight or longer I disconnect the
fuels hose and leave the motor running at the dock, to "Burn out" the gas
from the carburetor so it does not evaporate and leave the crud behind to
gum things up. After The motor stalls I put the line back on to store it
and keep water off the connectors.
At year end, I use the spray "carbon out", change the oil, gear lube,
and frog the engine, pull the plugs, spray some froging oil in and put
back fresh plugs. General cleaning with carb cleaner, Boeing guard, grease
up the right spots. put it to sleep
On the starting question:
- 1) open the air vent on the gas tank
- 2) Prime the fuel hose until hard and gas in the carb.
- 3) set the motor in neutral, throttle at the neutral stop
- 4) push the button for about 3-4 seconds. (90% that's it, one push)
- 5)if the motor does not start after the 3 pushes, put motor into
forward gear, turn the throttle from idle to full a few times and go back to
- 6) turn down the throttle to a mideum idle after about 10 seconds and
a slow idle about 2 mintues later(weather dependant) to finish the warm up,
I like to warm up the motor for about 10 minutes on cold days and less in hot
weather. If it's the second use of the day and a stall is no big
deal(away from the dock) I might only warm the motor for a minute or two.
25 May 2001
When Elton delivered, our boat he did more than bring rain, he also
brought considerable experience. His advice for starting the Yamaha, shift
into forward gear, this allows you to call for more gasoline than you can
in neutural, give the throttle a good turn, shift back into nutural and
hit the start button--it works for me!
K.Wise s/v Awaken
25 May 2001
This weekend our boat and 9.9 turn one year old. My starting process
has evolved over that time. Here's what's been working best:
- 1. make sure vent in gas tank is open and bulb is squeezed until hard
- 2. shift to forward or reverse and twist throttle to wide open and
back about 6 or 7 times.
- 3. shift back to neutral and open the throttle as far as it will go in
- 4. push the start button.
The motor has always started on the first try using this method. I
usually let it warm up for 5 minutes or so while I'm getting everything else
ready to go. I haven't been disconnecting the gas line and running the
motor out of gas recently, and I haven't had any problems so far. I've left it
for as long as 3 weeks and it's still started right up.
26 May 2001
I have an older 9.9 (1992). The carb has gummed up a couple of times
where I had to take it in and have it cleaned professionally. On a couple
of other occasions I was able to clean it out enough myself. I almost
always run the gas out of the card. The last time in the dealer showed me a
drain at the bottom of the float bowl, where some gas always stays. He
said to unscrew this and let the gas out. As far as starting, when the
carb is clean, I just hit the start button and after two or three
revolutions, the engine fires up. On occasions when it has not, it was
because I was distracted and forgot to put the safety tab & cable in place.
26 May 2001