1985 mariner 150 magnum-no spark on 4 cyl

[88champion]

have a 1985 mariner 150 magnum that has no spark to #'s 1,2,3,5 cyl's. 4&6 have good spark... problem started last weekend,acted like it ran out of gas,fired up but wouldn't stay running,rebuilt fuel pump,replaced plugs....checked comp and is 120 psi across all 6 cyl's....has 2 separate cdi box's..could it be that one took a dump and the other is going? I am at a loss here. any help would be GREATLY appreciated

 

[Laddies]

Re: 1985 mariner 150 magnum-no spark on 4 cyl

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[88champion]

Re: 1985 mariner 150 magnum-no spark on 4 cyl

I thought this was repair and maintainence

 

[j_martin]

Re: 1985 mariner 150 magnum-no spark on 4 cyl

Try disconnecting the kill circuit from the switchboxes. (black/yellow stripe) Then check for spark.

Next would be to acquire a DVA and test the stator and switchboxes.

hope it helps
John

 

[robroy]

Re: 1985 mariner 150 magnum-no spark on 4 cyl

DVA is the way to go, but there is other paths that will help you narrow it down. you can switch the two switch boxes out, and see if you really do have a bad switch box, or just a bad stator or trigger input. If the problem follows the switch box to the 2,4,6 side, then a bad switch box, if not look for bad stator/trigger. If you do have a bad switch box, don't just replace it, do the DVA test. No need burning up another switch box for nothing. Ask me how I know.

 

[j_martin]

Re: 1985 mariner 150 magnum-no spark on 4 cyl

DVA is the way to go, but there is other paths that will help you narrow it down. you can switch the two switch boxes out, and see if you really do have a bad switch box, or just a bad stator or trigger input. If the problem follows the switch box to the 2,4,6 side, then a bad switch box, if not look for bad stator/trigger. If you do have a bad switch box, don't just replace it, do the DVA test. No need burning up another switch box for nothing. Ask me how I know.

Look this over. It seems to sort out to DVA, and for good reason.

Proper diagnostics are the best way to limit parts expenses.

hope it helps
John

 

[Laddies]

Re: 1985 mariner 150 magnum-no spark on 4 cyl

As j_martin said the DVA is the only way to find difficult problems with a ADI system but while you waiting for one you might try disconnecting the bias wire between the 2 boxes as a bad bias in one box can keep the other box from working right, also if that don't help try disconnecting the 2 yellow wires from the reg/rectifier a shorted rectifier will also give one fits.