coil vs powerpack?

[neurofish]

25hp tiller 1986 Mercury is the victim<br />No (or very rarely) spark in lower cylinder. I switch the green wires coming from the power pack going to the coils and get good spark in the lower but then not in the upper. However, it will not run in this configuration (it would with spark in the upper). I am unable to switch the plug wires as they are part of the coils. Am I looking at a half blown power pack or some other problem? Thanks.

 

[ODDD1]

Re: coil vs powerpack?

neuro, you are right. half the pack is blown...time for a new one.

 

[Rock Man]

Re: coil vs powerpack?

I have 1986 90hp mercury and the power packs went (switch boxes as merc. calls them) Replaced them and gained about 700rpm and blew motor up last week or so. Doing rebuild right now. But yes replace if haven problems. Sounds like yours need to be replaced. Mine was doing same thing. Would fire sometimes not others.

 

[neurofish]

Re: coil vs powerpack?

That's what I was afraid of $$$. Do you always buy new ones or is this something that you can buy used? Thanks.

 

[neurofish]

Re: coil vs powerpack?

Anyone have any ideas why it will not run with switching the leads going to the coils? I know there is a good spark (good spark while holding it against the head). If you switch the hot wires going to the coil and do not switch the plug wires (i.e., not fully isolating the switch to the coils but just changing the hot leads) should it matter or is this the reason it won't run? If so, then if I switch the hot leads going to the coils and then change the plug end of the plug wires so that they attach to the other plug will it then run? Does any of this make sense?

 

[ICEMAN]

Re: coil vs powerpack?

HI, There are different ignition systems on various motors, My guess on your engine is the ignition system fires one spark plug at a time, therefore if you switch the wire from the switch box to the coil, without switching anything else, you have made the motor fire the other cylinder at the wrong time. It will not start. You would have to switch the coil to spark plug wires also. If you moved the switch box green wires and the problem moved I would suspect the switch box, if the problem stayed suspect the coil.

 

[petryshyn]

Re: coil vs powerpack?

Hi neurofish<br /><br />It won't run with the plug wires tandemed, cause it will fire one or the other but not both.(the electrons will choose one path or the other) Some systems operate like this, but the coil is a special design....<br /><br />sounds like new pack time (as ODDD1 suggests)....

 

[neurofish]

Re: coil vs powerpack?

Thank you to all the replied. Spoke with my local guy as well. He agreed that the motor won't run with just switching the wires because it puts the timing 180 degrees off. I bought a new power pack (switch box) and it runs like a champ. Look out, here I come.