Motor runs with my hand over intake

[Billy's Boat]

1st big motor I've ever owned .. it's a 96 Mariner 9.9, 4 stroke .. while I'm holding my hand over the air intake, motor runs great. When I remove my hand from the air intake - the motor dies. Have a fishing trip planned for Wed - please help if you have any ideas. I don't know what I'm doing .. thanks!!

 

[matt9923]

Re: Motor runs with my hand over intake

If you don't know what your doing your out of luck.
Check the 2 bolts around the carb see if their snug (don't over tighten).
You probably need a carb rebuild. That will be like $60 or less at the hsop idk if they can get u in before wed. Sounds like an air leak in the carb.

Did you have it running before?
Matt

 

[tashasdaddy]

Re: Motor runs with my hand over intake

air leak, high speed jets, some type of fuel restriction.

 

[Billy's Boat]

Re: Motor runs with my hand over intake

It was running when I took it to the lake, not the best, last Sunday - but it stayed running at 100% (at high speed). Tested in barrel on Tuesday and it wouldn't idle and sounds worse at 100%. Took the carburator apart today and cleaned all the ports, but it still will not keep running unless I put my hand over the intake.

 

[rtpassini]

Re: Motor runs with my hand over intake

its obviously a fuel or air problem. on certian motors when you unplug vaccuum lines, the idle will jump up.

or maybe you are running super lean and now that you are finally restricting the air flow, its running at the right mixture.

 

[matt9923]

Re: Motor runs with my hand over intake

the problem with the older motors is once something like this happens you need to replace form the fuel lines to the carb kit and needles. Get a carb kit and a new fuel pump as well as new fuel lines. this will be under $50. Or you could spend $60 on a vacuum pressure pump and test everything.
Matt