Mercury outboard stalls

[ytmike]

I have a 1979 mercury 900 series 90H.P. motor. The problem that I'm having is that when the boat is idling and I go to jump on it the motor dies out. If I bring up the throttle slowly it runs great threw the full throttle range up to 4600rpm. I just had the whole distributor unit replaced.(very expensive)could this be the carburators not set right or maybe the plugs going bad. Please help, Thanks

 

[12Footer]

Re: Mercury outboard stalls

Yes, weak spark will flood the cylinders with<br />unburnt fuel, and the motor will hestitate badly.But it allmost surely would miss under continuous throttle. But change the plugs with a fresh set.<br />Run the motor to operating temp.Gun it till it stalls.Pull the plugs. Are they wet or dry?<br />WET, weak spark or too rich fuel. Turn the idle mixture screws counter clockwise 1/4turn.<br />DRY; Too lean mixture. open mixture screw 1/4turn.<br /><br /><br /><br /><br />------------------<br />Time to change my tagline

 

[MERCMAN]

Re: Mercury outboard stalls

SET YOUR CARB MIXTURE SCREWS TO 1 3/4 TURNS OUT FROM LIGHTLY SEATED AND MAKE SURE THE THOTTLE SHAFTS ARE SYNC PROPERLY THEY SHOULD BE COMPLETELY CLOSED AND SHOULD ALL OPEN AT THE SAME TIME YOU ADJUST AT THE BLACK PLASTIC SHAFTS THEY ALL NEED TO OPEN AT THE SAME TIME OR IT WILL BOG

 

[ODDD1]

Re: Mercury outboard stalls

Mike, bogging on acceleration is a common problem on these engines...is almost always a carburation problem...unless distributor/timing was incorrectly done.....curios about model year, I thought last year for distributors on these motors was '77.....next time you are out in the boat and it is bogging tap the choke and see if the motor pulls out of the bog.....if it does you are lookig at a fuel prob.