90 mercury jet(force) starting turning over prob! help

richjms

Cadet
Joined
Aug 21, 2008
Messages
6
ok i boaught a 1994 jet boat with the mercury jet sport motor told its actually a force wish i had known!! anyway the guy said that he had too start it using lubricating starting fluid !! HE HIT THE KEY FIRED RIGHT UP RAN PRETTY GOOD IT SEEMED HE SAID HE HAD TO IDLE UP THE ENGINE TO KEEP FROM STALLING ANOTHER HUM!! ANYWAY NOW IVE GOT IT HOME BACKED INTO WATER TURNED OVER SEVERAL TIMES FIRED UP FOR 15 SEC. AND FELL OUT, TRIED STARTING AGAIN CHOKET IT UP AND THEN STARTED GETTING REAL WEAK WENT FROM RRRRRRRR TO R R RR RR R R SOUNDED LIKE BATTERY WAS DEAD CHARGED BATTERY SAME THING HAS NEW STATOR REV LIMITER ,SWITCH . CLEANED THE CONNECTION ON THE SILINOID AND BATTERY ALL , WOULD STARTER CAUSE THIS REACTION? PULL THE PLUGS OUT AND IT WILL TURN OVER LIKE A MAD MAN NATURALLy! WHAT CAN POSSIBLE BE THE PROBLEM? ANY IDEAS AT ALL BEAUTIFUL BOAT BUT NO GOOD IN THE DRIVE WAY RIGHT?? THANKS RICHARD JAMES MILLERSVILLE FIRE DEPT.
 

maxum247

Lieutenant
Joined
Sep 18, 2007
Messages
1,363
Re: 90 mercury jet(force) starting turning over prob! help

Take the battery and have it tested and make sure it's good, it takes some juice to crank this type engine. While you've got the spark plugs out do a compression test on each cylinder and note the readings, this will give you a base line to work from. And give you a pretty good idea of the mechanical condition of the engine. Readings should be within 10 to 15 pounds of each other per cylinder. You can pick up a screw in type compression tester at walmart for about $23. The other thing to try is to clean up the shaft on the starter and put a little white grease on the starter shaft so the pinion gear will engage in the teeth of the flywheel smoothly, it is possible that it may be hanging up a little. The starter solenoid could have high internal resistance and need replacing or the starter may be on it's way out and need replace or rebuilding. At any rate check the compression first and see what the numbers are.
 

rice

Seaman Apprentice
Joined
May 25, 2008
Messages
48
Re: 90 mercury jet(force) starting turning over prob! help

hi there. i have the same problem with mine. did you ever find out what was wrong?
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,799
Re: 90 mercury jet(force) starting turning over prob! help

Very likely a starter problem.
Take it apart, clean it out, or replace it.
 
Joined
Sep 1, 2008
Messages
13
Re: 90 mercury jet(force) starting turning over prob! help

I had a simular problem with a mercury 120 jet. The motor end bushing of the starter was worn badly- lots of lose play. replace the starter and it was fine. Now I am trying to find a bushing for the old starter to have a spare. any sources?
 
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