weak fire

[markcv]

I have a 1986 mercury outboard motor. Over the weekend while fishing the motor would not start after I shut it off. It is a electrical problem. The fire is real weak.<br />I have tried new plugs, checked all and cleaned the grounds. I have removed the fly wheel to do a visual inspection of the wires on the stator. Looks ok. I was testing a few things with a fluke meter. Yesterday I had no fractory readings on what the CDI or the Stator should be. I have got them today and will try to trouble shoot further after work tonite. Has anyone seen something stupid like bad ingction switch or bad kill switch to cause week spark. The only reason I ask is the motor started while I was performing a couple test. I did not have the muffs hooked up so I had to shut it off.<br />As soon as I got ready with the muffs on it had week spark and not even kick.<br />OH the reason I say it is weak spark is, it is very hard to see and I have sprayed a little starting fluid in the cylinders and installed new plugs, not even a kick. It should at least kick I should think.<br />How strong should the spark be? I have worked on snowmobles all my life and I believe tha being a two stroke like a snowmobile it should have the same strong spark??? Any help would be greatly taken.<br />Maybe a CDI, Stator, or kill Switch, or igntion switch.

 

[12Footer]

Re: weak fire

Any one of the things you mentioned could be suspect. Add to this, all connections involved with them.<br />It sounds like a bad connection,as you describe an intermittant problem.<br />Is the battery strong,and the starter drawing the normal current?<br />Try pulling it over with a rope (yea,I know..A real elbow dislocator)...But just to see if the spark is normal,and maybee caused by a battery/starter undervolt problem.<br />Good luck with it.

 

[markcv4]

Re: weak fire

Thanks I will try the rope

 

[markcv4]

Re: weak fire

Oh one more question. I have done some of the test on my motors system. It seems that all the voltages are right except one thing.<br />I have no voltage coming out of my switch box to my Ing coils (green wires). I have checked them to ground and also across them, nothing. The chart that I have says IGN TO COIL CRANKING 180V+ Am I checking this in the right spot. Shouldn't I have voltage coming out of the switch box to charge the main coils. Do you think I have a bad switch box????<br />Any help?<br /><br />Mark

 

[12Footer]

Re: weak fire

What HP is your Merc? Yes, the switchbox should give the coil 180V or more, but need to know HP to find color code.<br />Sounds like you got it narrowed-down

 

[ODDD1]

Re: weak fire

Mark, you should be able to jump a 7/16" gap when cranking the engine, any less is too weak...you gotta check the power coming out of the stator[red and blue wires] the red are high speed and make less than 90 volts cranking...the blue hhould make at least 180v...if all cyl are weak you probably got a failed low speed stator....

 

[markcv4]

Re: weak fire

The Horse power is 35. I did not see any blue and red wires. I thought the stator is located under the fly wheel in the back. The coil in the front is the charging coil I think???? The wires from what I believe is the stator are going to the switch box. The color is black/yellow and black/white. When cranking the motor I have 9.7 volts on the black/yellow and on the black white I have .5 volts. The other colors of wires on the switch box are brown/yellow and brown/white. brown/yellow has 32v when cranking and the brown/white has 34v. The other two place that has wires on the switch box are the green/white. There is two of them and they go to the coils that fire the plugs. I have no voltage on any of them.<br />It sounds like you think my stator is weak charging the switch box?? Is 9.7 and .5 volts week? It sounds like it If is suppose to be 180v. Am I in the right test location, I think I am. Well there is some voltages, I know with all of your expertease we will concor this problem. Thanks again guys. looking foward to you reply.<br /><br />switch box # oe 339-7452A3<br />stator # 86617A20<br /><br />Mark Seavey

 

[ODDD1]

Re: weak fire

sorry, Mark...I assumed you had a larger engine....your black/yell and blk/wht are your stator wires....outputs seem very low,but I am not comparing apples to apples....I use Merc's meter to test, dont know if the fluke would read the same....an ohms test would be the finaL say on the stator but I dont have numbers handy...

 

[Big Rod]

Re: weak fire

markcv4,Hi, Had the very same problem on a 48 Johnson, took two days to eliminate.It turned out to be a shorted kill wire(blk/yel)within wire harness (eng. side).Disconnect control box from engine harness and jump solonoid to eliminate switch and possible short in control box side.It's worth a try...Good luck.

 

[markcv]

Re: weak fire

Last night I unhocked the kill switch, extra yellow and black on the switch box. Per the info that I have on my motor. I guess the big question right now is: Am I suppose to have 180v+ coming out of my switch box to supply the Ignition coils, or am I suppose to have 180v+ coming from my stator suppling my switch box. I have no 180v+ anywheres. While I am cranking. We will get this narrowed down I think. HELP!!!!!<br /><br />Mark

 

[markcv]

Re: weak fire

Maybe the voltages that I am reading are different than I will get with a DVA meter.<br />I have a fluke and I am reading on the DC scale. The charts that I have are all in DVA readings. I still think that the switch box should have some sort of voltage coming out to supply my ignition coils? I am reading nothing. I am putting voltage in with my stator. Is it enough ????????<br /><br />Markcv

 

[markcv4]

Re: weak fire

Thanks for all your help. Just got my problem cured. It was my stator. Did an ohms check and it was open. I just installed a used stator on it. The boat shop did not have a new one. It seem to work fine. What is everyones thought, buy a new one anyways or use the one that I have installed. The motor runs excellent now. <br />Looking back and this may help everyone, My motor was stalling a little bit last year at the end of the year. That is when I would put it in gear. The problem was also present when i took the boat out this year.<br />With the new stator (used) that problem went away. Maybe a little sign of a stator getting bad???? <br /><br />Thanks for all you help guys, it really helped me narrow my problem down. I hope I can help some of you guys with your problems in the future.<br /><br />Markcv <br /><br />The smallmouth in the great State of Maine better watch now! lololo

 

[12Footer]

Re: weak fire

I went bass fishin today,Mark...Din't get a single keeper! <br />I guess they are bedding now,and wont hit a lure for anything..But the trip wasn't a total bust.I found 2 old Force outboards in about 6 feet of water.....PARTS!!!!!