1989 Merc 9.9 stalls

[jbinks]

I just purchased a used merc 9.9. As far as I can figure, it is a 1989 model. This particular engine was in moth balls for two years prior to my buying it.

It starts beautifully but when I put it into gear it stalls (sounds like lack of fuel). It will then start immediately after pumping the bulb on the fuel line, but when I put it into gear the same thing happens. Usually, on the third try (pumping the bulb again) everything operates as it should and it runs perfectly.

Whether the motor is cold or warmed-up doesn't change the process. It happens every time.

Any ideas on why it stalls and what I should/could do to fix the problem.

 

[rg2]

Re: 1989 Merc 9.9 stalls

If you do not put it in gear and just leave it in "N" idleing - Does it keep running or does it stall then as well?

I'm assuming this is a 2-stroke motor.

 

[fresno150merc]

Re: 1989 Merc 9.9 stalls

should check your fuel pump. might have a bad diaphram. easest way i've checked was with a clear line from the pump to the carb. look at it when it's running and see if it has constant flow. if not you have a problem from pump back to tank.

 

[BassnKY]

Re: 1989 Merc 9.9 stalls

You might also check for

A) Leak in the fuel line (Look for bubbles).
B) Too low of idle setting.
C) Dirty carb.

Just a few other things to consider.

However, since you have to pump the ball back up, start checking with the fuel supply system (i.e... fuel pump, fuel line, and pick-up)

 

[jbinks]

Re: 1989 Merc 9.9 stalls

Thanks for the quick responses.
The motor is a two stroke. It idles well when left in neutral and does not stall. I keep thinking or at least hope it is something simple. I will check the fuel flow when running. The idle speed seems OK...any higher would cause the motor to really jump when put into gear.
Would carb cleaner help or do I need to have the carb cleaned or rebuilt?

 

[BassnKY]

Re: 1989 Merc 9.9 stalls

Just a thought, on my 60hp, the idle is increased sightly when it is put in gear by the linkage.
Does yours have a similar setup?
What is the year and serial number. (You have to look up schematics on a Mercury by the S/N)

 

[jbinks]

Re: 1989 Merc 9.9 stalls

Thanks,
I am heading to my camp (cottage) today and will get the serial number and reply when I get back.

 

[jbinks]

Re: 1989 Merc 9.9 stalls

Hi all,
Didn't get to the cottage when I thought. The sn. for my motor is 0A747893. I found this number on the transom mount. Can anyone tell me the year

 

[BassnKY]

Re: 1989 Merc 9.9 stalls

It is hard to tell from the diagrams have you tried speeding up the idle just a little.
For the year, check the 1st thread in the Mercury post.