still trying

[novabrg]

I have posted on this subject already - thought i would try another approach to see if i can get additional input/ideas.<br />anyone have any suggestions on what would cause a 1990 120 horse merc inboard/outboard to die out as if the power was turned off - considering it has several coil packs it has been suggested that the coil is not likely and i think i may agree also the kill switch has been mentioned but that doesnt seem to make a difference. it died out and would not try to bust off or fire although it cranked strong and fine. then several hours later started right up on the first crank and ran a couple of miles and dies out again. i have gone over and over the wires and connections and they all look to be in good shape and clean. I have gotten some great help on here however i still am over looking something - i recently replaced the key switch and took it out for about 8 hours one day and it ran fantastic then the next day we went out it did really well for about 30 min and then this problem developed - after sitting for several hours like i said it started right up and while it was running it was strong and perfect seeming. such a mystery!<br />again thanks to you all for your input!!

 

[Mahoney]

Re: still trying

Yup, sounds like something in the ignition wiring is grounding out somewhere. No easy solution, just trace all wires around till you find the culprit. If you replaced or serviced anything recently I would start there. Its easy to hook a bracket back p and have a wire move to a location it wan't at before, just enough to let it ground out when bouncing along the water.

 

[jeff13601]

Re: still trying

When it stalls and will not start have you pulled a plug to see if you are getting spark?

 

[novabrg]

Re: still trying

yes sir i did check for spark - im not sure i did that correctly i did it the way i would in a car i left the spark plug in the plug wire and held it close to the block figuring it must be grounded and no spark - then i tried holding it against the block still no spark - again im not satisfied that i did that properly - someone told me to hold a screwdriver close to the end of the plug and look for the spark to jump but i didnt feel that good about that cause i thought the screwdriver wouldnt be grounded in the system so i didnt do that but maybe you could tell me the proper way to check that on a boat if im not doin it right the plugs are obviuosly made alittle differently

 

[hoot]

Re: still trying

i think i would do a complete tune up. replace all parts including rotor and cap. check gas tank vent line for blockage. couple of things; next time it happens, pull a plug wire and hold it close to plug, try to start engine and watch for spark. pull spark arrestor and hit throttle and see if gas in being squirted into carb. check your fuses. sometimes there are some in ignition/key switch wiring that are hard to find.

 

[Limited-Time]

Re: still trying

novabrg,<br /> In order to find the problem you need to be able to verify power to the different components in your ignition system. So the first thing you need to know is where the ignition wires run, and where you should have power. A service manual and a test light or electrical meter are a must. If your engine will run on muffs, with your boat on the trailer, that’s a good place to learn what should be happening, and at what points to check for 12 vdc. Then take your boat and test equipment to the lake and try and duplicate the problem, then start checking for power. Just be sure to have a tow boat ready incase you can not fix what you find wrong. Good Luck.

 

[jeff13601]

Re: still trying

To check for spark I scrape the paint down to bare metal and touch the base of the plug to the metal while someone cranks the engine. Do you have points? I agree that a complete tuneup might solve the problem. If not you need to clean wires and find the bad connection

 

[novabrg]

Re: still trying

thank you guys - very much appreciated

 

[olbuddyjack]

Re: still trying

I think bluewater hit on something on your other thread. Is this an L-drive?<br /><br />If so you can post a question in the Chrysler/Force outboard section. I've heard something about cd boxes or such being a problem on certain year Forces. (If its an L-drive its a Force power head even though it says Mercury)<br />"Baseyball been bery bery good to me. Outboards, idonno."

 

[bigdaddyofhouse]

Re: still trying

does that motor have a spark control modual or even a pick-up coil? thats what it sounds like to me.

 

[pine island fred]

Re: still trying

Long shot but look for a small plastic block in the wireing system. Would be a KLIXON circuit breaker that has no indication that it is open and resets on its own when it has cooled. One i encountered was not on the print and was factory installed. Pulled a lot of hair out on that one. fred