1986 25 HP Mariner (Won't start)

[Dog1234]

Hello................ As stated above I have a 25 HP Mariner. Its been running GREAT for two years now. I use almost every weekend in the summer only. Last weekend while running jugs it had a very small miss I detected while idling. So I figured I would change my plugs as they were old and possibly clean up the miss. I changed the old plugs with new one, went to the local landing to put out some crawfish traps and it did not start. I ripped a hole in my skin trying to start it............... I pulled the plugs and found out that they were not firing. An interesting event was that at the end of each pull cycle of the started rope the spark plug would give out one spark (on the last revolution on the crank shaft)????????????? I can also hear a little click as this on spark happens. So I got home and put in old plugs and the same happens. One spark at the end of the cycle. One other interesting fact is that the one spark I can get it to inconsistently produce does not spark on every pull, but I do hear that click coming from somewhere.

I just tried it again this morning. No spark from plugs but I did get a shock as that click sound happened while holding the plug wires. Also with both plugs just hanging from the plug wires I pulled the rope and noticed one spark from the side of the lower plug to the latch that secures the hood as the click sound is heard also. The spark is about 1.25 inches long.

ANY HELP WILL BE GREATLY APPRECIATED!!!!!!

It may be a 1995 model I am thinking if that help trouble shoot the problem.........................

 

[gm280]

Not sure what year your engine actually is, but I looked up both a '86 25 HP and a '95 25 HP models and both use a trigger ignition setup. So maybe your trigger is going bad. Sounds more intermittent and you may need to remove the flywheel and see what's underneath to see if all connections are good and if the parts are secure. Either you have some wires loose or one of the ignition parts starting to go bad... Best I can say without further info or begin there and testing things myself.... JMHO

 

[Dog1234]

Do you have a parts break down or something that shows me these parts and their names? Or where I can locate on?

 

[Guest]

hopefully this helps

 

[Dog1234]

Serial Number 0G121481. it looks like a 95 model.

I pulled the fly wheel the Trigger assembly alone with the starer assembly look good. They are tightly secured in place and I see not broken wires. Is their a way to check the electrical components with a multi meter?

 

[gm280]

Dog1234, I went to a boat site that sells parts and they show a few model numbers for the '95 25 HP Mariner engine. The site is:
http://www dot boats dot net/parts/search/Merc/Mariner/1995/7025201DD/parts.html You will need to remove the dots and replace with a actual dot for it to work. But there are many models of your engine for that year... How that helps you out... :thumb: