2002 YAMAHA 50 HP 4 STROKE NEED HELP

[imported_SCOTT1]

I WAS FISHING IN MS, ALL MORNING BOAT RAN GREAT THEN OUT OF NO WHERE A LOAD CLANKING NOISE CAME FROM UNDER THE FLY WHEEL CLOSE TO THE STATOR, AND THE MOTOR STOPPED WOULD START BACK UP BUT STILL HAD THE NOISE, WELL LOADED THE BOAT UP WENT HOME AND NOW THE MOTOR WILL TURN OVER BUT WON'T START. PLEASE HELP I AM ABOUT TO GO BACK OVERSEAS AND WOULD LIKE TO TAKE MY SON FISHING ONE MORE TIME.

 

[rodbolt]

Re: 2002 YAMAHA 50 HP 4 STROKE NEED HELP

about the only thing to do now is remove the flywheel cover and look for anything loose, if nothing is found then remove the flywheel and keep looking.
could be the stator or pulser coil holder has come loose.

 

[imported_SCOTT1]

Re: 2002 YAMAHA 50 HP 4 STROKE NEED HELP

OUTSTANDING, IS THERE A BEARING OF SOME SORT UNDER THEIR. WHAT CAN I DO TO ELIMINATE THE PROBLEM IS INSIDE THE MOTOR?

 

[rodbolt]

Re: 2002 YAMAHA 50 HP 4 STROKE NEED HELP

first ya have to determine is it IN the motor or UNDER the flywheel.
the stator on that model has a few functions.
I dont have my manual here and there have been changes over the years but let me tell you if a pulser coil,coil holder or stator mounting screws back off the noise is nasty.

if you suspect a rod came loose then remove all spark plugs. rotate the engine in its normal direction while feeling for TDC with a screwdriver. once TDC is found rotate the flywheel 45* more. then while holding the flywheel push on the piuston. if you feel the piston move and the flywheel doesnt you may have internal damage.
your ign system is still ADI so if the stator or charge coil mounting screws come loose not only will they hit the flywheel odds are it wont spark.
best I can tell you other than with the correct thread bolts, a standard harmonic balancer puller and a strap wrench or flywheel turning/holding tool is all that is required to pop the flywheel.
if there is internal damage your not going fishing, if something is loose and not damaged you may be able to.

 

[imported_SCOTT1]

Re: 2002 YAMAHA 50 HP 4 STROKE NEED HELP

WOULD THAT ALSO CAUSE THE BATTERY NOT TO CHARGE, BECAUSE WHEN WE LEFT EVERYTHING WAS CHARGED AND NOW THE BOAT IS DEAD I HAD TO RECHARGE IT. NEW BATTERY

 

[rodbolt]

Re: 2002 YAMAHA 50 HP 4 STROKE NEED HELP

yes it will,

the stator is just that, its a STATIONARY coil of wire. when the flywheel magnets rotate around the STATINARY coils it generates an AC voltage that is fed to a rectifier/voltage regulator where the ac is converted to Dc and the voltage output is regulated to below 15 volts.
if the air gap is not correct it fails.

 

[imported_SCOTT1]

Re: 2002 YAMAHA 50 HP 4 STROKE NEED HELP PLEASE RESPOND

Re: 2002 YAMAHA 50 HP 4 STROKE NEED HELP PLEASE RESPOND

THANK YOU VERY MUCH FOR THE ADVISE. I CHECK THE STATOR FLYWHEEL ETC. WITH EVERYTHING OFF I TURNED THE SHAFT WITH A SOCKET AND IT MADE A REALY BAD SCRATCHING NOISE. BEFORE I TOOK THE TOP APART I CHECKED COMPRESSION FOR BAD RINGS AND BOTH COMPRESSIONS WAS GREAT, I ALSO STUCK A LIGHTED PEN MIRROR IN THE CYLINDERS TO CHECK FOR BAD SCRATCHES, VERY SMOOTH. SO DUE YOU THINK IT COULD BE THE SHAFT BEARINGS OR SOMTHING IN THAT AREA? WHEN ALL PLUGS ARE OUT NO NOISE, BUT ALSO THEIR IS NO COMPRESSION SO PLEASE HELP I GREATLY VALUE YOUR HELP.

 

[overthere]

Re: 2002 YAMAHA 50 HP 4 STROKE NEED HELP

Rodbolt is this a common problem with these engines?

about the only thing to do now is remove the flywheel cover and look for anything loose, if nothing is found then remove the flywheel and keep looking.
could be the stator or pulser coil holder has come loose.

 

[rodbolt]

Re: 2002 YAMAHA 50 HP 4 STROKE NEED HELP

not a common thing but I have seen it on all makes of outboards.