1994 Mercury Sport Jet 90 - bad ignition parts

[hjrader]

I have a 1994 Dynasty Jet Storm with a Mercury (Force) Sport Jet 90 motor. The motor just died on me as I was in the process of starting it. It had run fine the day before.<br /><br />We determined that there was no spark being produced. I ran the tests in the Clymer manual and discovered that the rectifier has gone bad.<br /><br />In looking through this forum, I've read that stators and switch boxes from this year are not good and liable to go bad.<br /><br />Part 1.<br /><br />What I want to know is, if the rectifier is the only thing bad at this point, will the other two parts inevitably go bad on me while I'm out in the middle of the river somewhere and create a major hassle? <br /><br />In other words, can I get away with just fixing the one bad part, or do I need to bite the bullet and replace all three?<br /><br />Part 2. <br /><br />If I do replace the stator, would you recommend doing it myself, or is this a job for a tech - the tough part being removing and replacing correctly the flywheel? I'm moderately skilled at things like this but wouldn't want to endanger the occupants of the boat.<br /><br />Thanks a lot.

 

[jetdriven]

Re: 1994 Mercury Sport Jet 90 - bad ignition parts

Answer to Part I: <br />No. Don't replace all your old components. It's all solid state and will either function or not. I used to be skeptical of this, too. However, with the exception of the original black stator, the switchboxes and other electronics are basically OK. It seems like they cannot tolerate any shorting though, so make sure that your wiring harness and ignition switch have no bad connections or shorts! <br />The only time you may want to replace all the electronics is if your engine severely overheated and caused heat damage to the components, such as melted the casing of the stator, etc. If you haven't had anything this catastrophic happen, then just replace each component as it goes out.<br /><br />Answer to Part II:<br />You can replace the stator yourself. You can test it and the trigger without removing them, so do that first. There is no need to remove the flywheel unless your meter tests show that the trigger or stator are bad. I would guess that your stator was recalled sometime in the past and that it already has a red stator in the engine. Whatever stator you have, pay close attention to the label on that stator that shows which bolt holes to use for mounting. The new red stator will not have a label like this and will not show you how to properly align it. This is no problem if you pay attention to the position of your old stator, though.<br /><br />Finally, a bad rectifier/regulator cannot make your boat lose spark. If the battery became too weak due to loss of charging, then it could be the regulator/rectifier that allowed your battery to go low. The stator has two totally separate coils in it, one for the ignition system and one that acts as the alternator. These two coils function independently of each other and you can test them according to your manual. (Four wires come from the stator: two for the rectifier and two for the switchbox.)<br /><br />Good luck.

 

[hjrader]

Re: 1994 Mercury Sport Jet 90 - bad ignition parts

Thanks. I'll post what happens.