1987 80HP Merc NO Spark!

[SSG D]

I have been generously given a tri hull,with an 80HP Merc 3Cyl. My Friend said it would run fine for a little bit,then he would have to back off the throttle till just above Idle,and limp back to shore. He had enough,and now its my baby. Upon checking the basics, I have no spark on all 3 cylinders. I am awaiting the manual,But do have an electrical/mechanical backround,and know enough without wiring diagrams,not to probe around. I have been reading the threads,and can tell you that I have a black stator.the switch box is not dripping goo either. So my question is, WHERE DO I BEGIN??? what would be the first/most common place to start? I like to test things and not just throw parts.I believe in having test parts before i buy new,so i am looking for a mechanically blown engine.Any help will be greatly appreciated,SSG D

 

[SSG D]

Re: 1987 80HP Merc NO Spark!

OK, My friend just stopped and finally gave me the whole story.....like pullin teeth,i tell ya.
He dropped it off at the marina to have it checked out 2 weeks ago,First thing they did was a compression test... 120,120 and 100. Obviously,someone told him this was terrible,so he opted to drop 6,000$ on another boat. my question is this...if they did a compression test,they would kill the spark...coincidently,i have no spark...is there a wire or switch they would throw to kill the spark??? that they may not have hooked back up???

 

[tashasdaddy]

Re: 1987 80HP Merc NO Spark!

they would have grounded the plugs to test, compression may come back up with a decarb. here's elect test http://www.boatpartstore.com/page21.asp

 

[ddennis]

Re: 1987 80HP Merc NO Spark!

Check the coils..there is a post on here somewhere on how to check them with a multimeter. 120-120-100 ,..that one is a bit low... once you get it running seafoam the engine really good.. while you are waitin on the manual, pour some seafoam in the cyl's and let it soak to break up the crud. after it soaks for a day or 2 crank it over with the plugs out to blow the crud out and then try the compression test again.

EDIT>...DAGNABIT...tashasdaddy beat me to it again! LOL

 

[SSG D]

Re: 1987 80HP Merc NO Spark!

I will pick up the Sea Foam today.. Thank you... I have checked the Merc Switch...it has 2 wires. one going to the switch,and one up near the carbs....when i unhook it from the switch box,still no start. If I test just the switch ,to ground and move it ,it works as should.when i hook it up to the other blk/yel wire and test,i have continuity to ground till i crank it..should it be this way?

 

[SSG D]

Re: 1987 80HP Merc NO Spark!

Well,I just ohmed out the stator. The red wire to ground has 1.2 ohms,the blue wire to ground is open. Am I correct that the stator is junk??? is there anything I should replace with it?

 

[SSG D]

Re: 1987 80HP Merc NO Spark!

I have read and heard you should replace the trigger,and rectifier too. Is all this part of the new "red stator kit"? Or should I just upgrade to the red stator?

 

[jmburock]

Re: 1987 80HP Merc NO Spark!

The red stator kit doesn't contain a trigger or regulator. All it has extra is a little sealed black box that adapts it to higher amps. I would look into the CDI/Rapair stator. You probably don't need to change out the trigger. You may need a new voltage regulator. Do you have the 9amp or 16amp system?? Do you have a rectifier or the regulator/rectifier (2x2 box mounted on an aluminum plate w/ 2yellow/2red/1gray/1black wire) ?

 

[SSG D]

Re: 1987 80HP Merc NO Spark!

I am not sure which one I have.... It is a 3 cyl.the stator is black that I can see. I have 5 wires coming from the stator,1 blue and 1 red,both going to switch box.then there are 2 yellow wires going down to what looks like a sealed regulator,just 2 posts on it. and then of course a black ground. now I do see another bundle out of the front under flywheel,that has the white,and purple and a couple others....Am I lookin in the right spot???? I unhooked the 2 yellow wires from the regulator lookin box,and it still didnt start!!!!! If that book doesnt hurry,I am gonna torch this thing! Also,does anyone know where I can buy a mechanically blown motor? If I havent said it before,thank you guys for all youre help!

"Land of the Free,Because of the brave" OIF II

 

[jmburock]

Re: 1987 80HP Merc NO Spark!

Sounds like you have the original 9amp black stator with the rectifier. Must be one of the few Mercs left with the original stator. You don't have a voltage regulator. The purple and white wires are coming from the trigger under the flywheel and go to the switchbox. It sounds like you need either a new stator and/or a new switchbox. You can upgrade to a 16amp CDI/Rapair stator but you will also need their voltage regulator as you only have the rectifier. The CDI stator runs cooler as it is not encased in the sealed case and the windings are exposed to let out heat.

 

[jacobmorin]

Re: 1987 80HP Merc NO Spark!

Also I would check to see if there is a gasket that is worn or corroided and might be spraying water up into your plug area. This is only if you are not getting a spark with water hooked up or in the water itself.