help with ignition system-1996 mariner 200 magnum efi

[veritek_dragger]

Hey there John, its me again! Same problem, different boat! last remedy on the black max was replacing the stator- worked like a charm. Same exact issue with the new boat, but Im worried that I may have created the problem with the new boat. my cranking battery went bad, so I started the motor from one of the trolling motor batteries and then while the engine was running, tried to switch the leads back to the cranking battery- bad idea I know. Sparks and whatnot, so killed the engine and decided to run the motor now off of one of the trolling motor batteries (which note that is wired in series with another for my 24 volt trolling motor). harness however is only hooked up to one of the batteries. As far back as I can think, this is when the problems slowly started. its now to the point where I make a long run shut the motor down and when I try to take off, 3 cylinders of 6 intermittantly fire...once on pad and high speed stator windings kick in, runs great. I just got a new CDI stator but Im worried about installing it as I may blow this one too, maybe due to a shorted wire or reg/rect? Or do you think the damage was initially done and running the motor, the temps just progressively made it worse? Its a 96 Mariner 200 mag efi, 40 amp stator. water pressure and cooling are fine. fly wheel and main bearings are tight.

Im wondering if running the main harness off of one of those batteries wired in series may be the culprit?

Thanks in advance for your help Godfather of Mercs!

 

[CharlieB]

Re: help with ignition system-1996 mariner 200 magnum efi

It is more likely that disconnecting the battery while the motor was running created the problem.

While the battery was disconnected the rectifiers did not have a DC source to tell the regulator how much to charge. This may have allowed the system voltage to spike too high and damage one or both of the rectifier/regulator modules. Possibly causing damage to circuits in the EFI computer as well.

You should disconnect both rectifier/regulator modules and test each following the directions in the service manual.

Do a cranking spark test on all cyls, if any fail to provide a hot blue arc across a 7/16 inch gap then follow the tests spelled out in the CDIElectronics Ignition Troubleshooting Guide to determine the problem.

The fact that the motor does run and gains RPM may indicate that the EFI survived and you simply have an ignition problem. Let's hope so.