Help '87 Mariner 20hp, no spark on one cyl.

[rlsc98]

this is a 2 cyl 20hp 1987 Mariner, tiller handle,manual start. i replaced 1 coil because I was not getting spark on one of the cyl. I then replaced the switchbox with no luck still no spark on that cyl.The trigger and the stator would be the next on the list but via the Seloc repair manual which says if i put a Meter on the black\white wire coming out of the switchbox and the other lead on ground and turn the engine over I sould get a reading between 4-106 VDC, well I got 42VDC which means the switchbox is good and getting power.My ques. is why wouldnt I be getting spark to that one cyl. All seems good between the spark plug and the switchbox.Any help would be great,thanks,Ron

 

[JB]

Re: Help '87 Mariner 20hp, no spark on one cyl.

I don't have an answer for you, rlsc, but this will move you post back to the top.<br /><br />Someone will be along that can help.<br /><br />Good luck.

 

[phatmanmike]

Re: Help '87 Mariner 20hp, no spark on one cyl.

have you tried swapping coils to see if the problem moves to the other cylinder?<br /><br />it could be something as simple as a faulty spark plug, ive had it happen to me. it could be a cracked spark cable or a coil with a corroded ground or faulty ground

 

[Laddies]

Re: Help '87 Mariner 20hp, no spark on one cyl.

Ussally if that system fires one coil you may assume that the stator is providing enough power to run the engine. If you have spark on one cyl. the trigger is fine, as it uis just a winding that pulses of both ends ++ or -- so it has to be a complete cricut. That only leves a couple of things, you may have made the same mistake I did years back and not have the wire plug in right at the swich box, gotten a bad box. Reprove your system by crossingn the input wire at the coils and see if the spark follows the wire or stays with a coil. With a DVA the stator output is 180 v low speed, 20 v high speed, the trigger is 4 v + and output to the coils is 180v

 

[rlsc98]

Re: Help '87 Mariner 20hp, no spark on one cyl.

Thank you JB for the move to the top.<br />I have tried moving coils and wires with no avail. Spark still with the G\Y wire not with the G\W wire coming out of the switchbox which go to the coils.I guess ill go to the dealer i bought the switchbox from and see if he can test it. I have 47Volts coming down from the B/W wire from the CDI switchbox which from the Seloc manual I sould have anywhere from 4-106 VDC. So my headache continues,by the way this motor is for a coaches launch,My sons rowing crew, they need this motor badly as rowing season is around the corner.<br />Thanks again for all replies to this thread.<br />Ron

 

[DHPMARINE]

Re: Help '87 Mariner 20hp, no spark on one cyl.

I had this problem last year with a 35Hp.Drove me (and Merc Tech) crazy.<br /><br />Finally found flywheel magnet had let go,both magnets were side by each.All readings were correct,also.<br /><br />See if you can move the magnets under and inside the flywheel.You shouldn't be able to.<br /><br />DHP

 

[rlsc98]

Re: Help '87 Mariner 20hp, no spark on one cyl.

I will try on wed. morn and report back ,Thanks

 

[phatmanmike]

Re: Help '87 Mariner 20hp, no spark on one cyl.

http://www.outboardrepairs.com/manuals/

 

[rlsc98]

Re: Help '87 Mariner 20hp, no spark on one cyl.

Thanks ,myoutboards, but I already have a seloc manual.

 

[basse]

Re: Help '87 Mariner 20hp, no spark on one cyl.

Have you solved the problem. I have exactly the same problem.