1992 60hp Mercury-quits running

[Roberthill]

1992 60hp Mercury Ser#0D142687
Starts up and runs about 100 yds and quits .Does not appear hot . After waiting a while it starts up and runs about 100 yds and quits again . Where is best place to start looking . My first is coil but it has three so its not logical for all three to go bad at once .

 

[Texasmark]

Re: 1992 60hp Mercury-quits running

Ok then let's go after fuel. When it quits, did you try squeezing the bulb to force fuel into the carbs? If not do it and see if it helps. If so, look at fuel pump. Is the bulb collapsed when the engine stops? If so no vent to tank or clogged fuel line, bad squeeze bulb.

That will kick the can on down the road so to speak.

Mark

 

[Roberthill]

Re: 1992 60hp Mercury-quits running

Bulb was not collapsed , squeezed it up but to no avail , had to wait a while then motor started . I am assuming that there is no spark . This boat and motor belongs to a friend of mine up on Conroe Lake (about 90 miles from me) that has Parkinsons and he gets me to help him ,but before I drive up there I try to get all information I can .

 

[Texasmark]

Re: 1992 60hp Mercury-quits running

Got a timing light that is battery operated? Timing light that we used to use to set the timing on engines with conventional points, condenser and coil ignition systems. If you do, hook it up to the engines battery somewhere for power and put the sensor in the proximity of a spark plug wire. If it lights off when the crankshaft is turning you have spark. If not you don't. Merc has a complicated wiring diagram for their 3 cylinder engines and the signal source comes from the stator windings which are under the flywheel. You have iron core coils and a magnet imbedded in the flywheel. The coils are placed at 120 degree intervals around the flywheel and as it turns, the trigger magnet induces a trigger pulse in the trigger lines which ultimately fire the CDI modules in time.

Since you have zero performance it needs to be a common element which is the magnet embedded in the flywheel (Alnico 5 or such which almost never fail unless they fall off) or wiring problems to the 3 coils. Since there is one coil per cylinder, as you said one wouldn't expect all 3 to go bad at a time. Might check for corroded bayonet connections on the wiring harnesses.

HTH,
Mark

 

[Roberthill]

Re: 1992 60hp Mercury-quits running

Thanks,will try that asap.
Robert

 

[AChotrod]

Re: 1992 60hp Mercury-quits running

I have a 95 60 and my boat was doing almost the same thing but when/if it did fire I gave it throttle quickly it would run and stay running as long as I kept moving until I shut it down . Ended up being the stator. The low speed coil in it was dying it would barely get spark or have no spark. Changed stator and fires first crank every time.

If you can get it tested with a DVA meter. I did not have one and since the motor was older I just replaced everything but the coils. I knew it wasnt the coils since all 3 were doing the same thing. Started with the switch box, then regulator, then trigger and finally the stator. No change until the new stator went on. I wanted to do the stator first but had to order it and when It got here it was the wrong one, so I had to reorder it. Well at least I shouldnt need to worry about it for a long time now.

 

[Roberthill]

Re: 1992 60hp Mercury-quits running

Was not getting any spark . Pulled plugs checked compression , no compression on bottom cylinder now its rebuild or replace .

 

[Texasmark]

Re: 1992 60hp Mercury-quits running

, no compression on bottom cylinder now its rebuild or replace .

Bottom cylinder is usually hard to reach with a compression gauge. You aren't going to have a running engine that performs just fine when it decides to start with NO compression on one cylinder. You have to have a mechanism for NO compression and just what would you suspect? Nothing that drastic comes to mind for me.

I suspect operator error and forget the overhaul. Go after the spark. Numerous posts concerning a DVA are on here. I have described the circuit several times. Some have produced pictures. You can buy them on here or pull up one of the threads, go to radio shack, get 3 parts and build your own if you have a soldering iron and some 20 AWG or thereabouts wire.

Mark