Logo
FULL SITE MENU

Merc 125 wonbt start

B

bigd20895

New member
I have a 1999 Merc 125 that wo

I have a 1999 Merc 125 that won't start.

I have chaged fuel filter and fuel pump. Now I see its does not get any spark.

Heard that it starts on 2 cyc. which ones?

Thanks
 
"Check for spark on all cylind

"Check for spark on all cylinders, if no spark look for a black/yellow wire on the switchbox. disconect it and try spark test again. First check your man-overboard switch.

I think your question about starting on 2 cylinders is, it idles on 2 cylinders if it is a 2+2 engine. It will always have spark to all cylinders."
 
"I have a 1989 mariner 100 hp

"I have a 1989 mariner 100 hp serial#oc135659 4 cly.One day running good & next day cranks but will not start.Getting fuel,kill switch ok,spark plugs not getting fire.I have a oe service manuel.The stator was upgraded several years ago.I did the stator ohms test(not removed)with a digital multi-meter(radio shack)Removed blue & blue/white stripe wires from terminals & left black ground on.Book says I should get between 6800 & 7600 ohms & I get .737 ohms.I assume I need a new stator if I am doing every right!I would appreciate comments.....THANKS"
 
"I dont know the specs. but d

"I dont know the specs. but depending on where the meter was set x10, x100, x1000, a reading of .737 move the decimal point now reads 7300 ohms. Give or take. Do you have the black/yellow wire on the switchbox, if so remove it. It grounds the ign. So removing it removes the wiring, kill switch, ign key, mercury tilt switch and harness."
 
"JB....thanks for the response

"JB....thanks for the response.I thought the meter was automatic in ohmes but it is not.It was in 1000x so it read 737 ohmes it looks like to me,but I am more than likey wrong.I think .737 X 1000 is 737.I took the black/yellow off the switchbox,gave the throttle a little gas,choked it,and turned the key.It turns real fast but it will not run.It is a new meter but it may be wrong.I would appreciate any feed back..........THANKS"
 
"JB....I didn't touch the

"JB....I didn't touch the motor for a day.Went out 30 minutes ago,took the black/yellow stripe wire off the switchbox,squeezed the fuel bulb until hard,gave it a little throttle,choked it a few times & turned the key on to start it.IT CRANKED RIGHT UP!I went back to the motor to touch the black/yellow stripe wire back to the terminal to kill it.In doing so I bearly touched the two blue wires coming from the stator & it died like you turned the key off before I had a chance to do it.I tried to start it back up but to no avail.I checked the 2 blue wires for continuity & they were alright.I wonder if it might be the ignition switch......I don't know exactly what this means......will wait for your response.THANKS...."
 
"removing the b/y wire takes t

"removing the b/y wire takes the ign switch out of the loop. So with the b/y removed you can now use the key to start but when you go to turn it off the engine should stay running. If the engine runs then the key switch or wiring is bad. You can go to the cdi site and download the troubleshooting guide or get it here, I'm on the home comp with limited links
http://www.maxrules.com/cdi/TroubleshootingGuide.pdf"
 
"Sorry guys, been really reall

"Sorry guys, been really really busy.

Remove the two blue wires from the switchbox(s) and test with your ohm meter again. This time you are looking for continuity between each individual wire and ground (just find a good spot to put the black lead from your meter on the engine block).

It sounds like you may be going to ground - either at the stator itself (cracked bobbin) or possibly a rubbed bare wire somewhere under the flywheel (between the stator and the switchbox). That would explain why sometimes it will start (the wire gets jiggled enough that it loses contact with a ground source)...."
 
When the motor fired up I turn

When the motor fired up I turned the key off & it kept running & then I yanked the emergency stop switch out & it kept running(which is what I expected)and then it died just before I was going to touch the b/y wire back to it's terminal.This is what confuses me!The motor ran for 15-20 secs & an then quit on it own.It quit as if I touched the b/y wire back to it's terminal(which I did not do).I just now went out to start the motor(b/y wire off the terminal).I charged the batteries all night.The motor spins very fast but will not start.Did you mean(with b/y off)when you turn the ign. switch off(motor running)& it keeps running the ign. switch is bad or bad wiring!I am going to check that web site you suggested.THANKS........
 
"If it wont start with the bla

"If it wont start with the black/yellow disconnected the problem is in the engine. Now you should check spark at the plug/just to be sure its not a fuel problem. I would expect no spark at the plug.

Again, the black/yellow wire comes from the key/kill switch, when grounded the engine has no spark. So removing it at the switchbox means the ign is hot all the time. The ign doesn't need any battery power to work, it is self energizing. Like a push mower."
 
"galamb....Sorry but I did not

"galamb....Sorry but I did not see your post this morning until after I did mine....I did what you said and I get no continuity from either blue wire to engine ground.After doing the test I tried to start it but to no avail.I grounded to the motor at several places.I'm like you,after starting that one time,it has to be going to groung somewhere,I don't know.It,s got me (bumfuzzled).THANKS for the input,keep it coming."
 
Either the low speed winding o

Either the low speed winding on the stator is shot or those blue wires are broken. You should have got a reading on that test.
 
"Sunday am while looking at th

"Sunday am while looking at the switchbox I discovered the terminals are labeled for the color of wire and I had somehow switched the stator wires during one of my tests.I corrected that & it started right up.I am going to have to really watch it & not get too far from the boat ramp that my trolling motor will get me back.If it quits again at least I know where to go(STATOR)to fix it.I want to THANK everyone that gave me input on this.I have really learned alot about my motor,it won't intimidate me so much in the future.THANKS AGAIN......"
 
Back
Top