mercury 90hp sport jet ,loss of spark at plugs

i have a 1994?mercury sport jet 3 cyl 90hp non oil injection,number oeo33796 with the bullit type connectors.fitted in my bayliner jazz,<br />the engine has lost all 3 cylinders ignition,did have spark on cylinders 2+3 but now have lost them all,<br />did swap coils,plugs and leads bettwen cylinders 1+2 but there was still no spark on cylinder 1<br />(2 still worked)but now has lost all spark on all 3.<br />engine has just been rebuilt and not fired since,did work prior to strip down.had new pistons,flywheel,plug leads,loom conectors where needed,battery,gaskets+seals etc.<br />it has a red stator (2 yellow wires/2green/white wires)with mars bar size box on switch box(recall mod?).the wiring diagram doe,s not show the box and the green/white stator wires(manual shows red and blue) and there is a red wire coming from switch box thet is blanked off (stator wire?)and blue stator wire to mars bar box.<br /> any body have a wiring diagram with the later red stator and extra box from it as i have seen that the testing is different on the original and red stators .or details of stator mods/rework the dealers did while they were under warranty.<br />have checked and cleaned all connectors,earths etc.

Re: mercury 90hp sport jet ,loss of spark at plugs

hello<br /> that motor originally had a black stator with high and low speed charge coils. you now have a red stator kit. not a recall. and an ignition module adapter. mars bar size box. you will need a DVA or a CD-77 peak reading meter and the bulliten on testing the red stator.I have it but no clue what I did with it. the red lead used to be for the high speed leads on the black stator. so what you will bee looking for is something about 150V peak to the module and out of the module to the switch box. try dissconnecting the black yellow wire from the switch box first and rerun the spark test.

Re: mercury 90hp sport jet ,loss of spark at plugs

just did the voltage test on the green/white wires on cranking only had 60 volts a/c when cranking.<br />the resistance on the same wires was within what is expected,did not run with the black/yellow wire disconected.<br />is this a dead stator then.

Re: mercury 90hp sport jet ,loss of spark at plugs

ac is not peak. you have to have the correct meter to do the test. but with 60 volts ac I imagine the peak will be around 120 or better.<br /> I will look about this weekend and try to find my red stator manual. but without a peak reading multimeter its not gonna help ya much. what did you get for an output from the module to the switch box? test that with the box connected and dissconnected. at the blue switch box terminal.

Re: mercury 90hp sport jet ,loss of spark at plugs

Check every connector in and around your motor for burnt wires and/ or burnt connectors. My 75 HP 3 cyl was completely without spark until I found burnt, shorted wiring. Shorted wires keep the capacitors from charging. Give it a check. You never know. Good luck. Gennis G

Re: mercury 90hp sport jet ,loss of spark at plugs

have checked and cleaned every connector,earth point ,checked for trapped/shorted wires,<br />even replaced a few burnt/corroded bullit connectors.<br />battery is new and fully charged and cranks over at a good speed.<br />(rodbolt )do you mean the mars bar shaped box(module to switch box)

Re: mercury 90hp sport jet ,loss of spark at plugs

I meant check every wire that you can see and get your hands on. My bullit connectors were burnt.I'm no repair expert. Probably best to get a manual and run all the tests. Good luck. DG

Re: mercury 90hp sport jet ,loss of spark at plugs

have the clymer manual but it does not list red stator ignition.

Re: mercury 90hp sport jet ,loss of spark at plugs

Thats why most mechanic's like OEM manuals---Bob

Re: mercury 90hp sport jet ,loss of spark at plugs

the OEM manual for your force will not list the red stator test procedures. but there is an addendum for it and some of the later manuals have it. its the same stator kit that was used on the 2cyl,3cyl and 4cyl force and mercs from about 1991 or so till the CDM ign came out about 98 or so.<br /> I still have not found mine. but without the proper test meter the manualis not going to help. the mars bar looking module is basically a voltage regulator. test the input to it from the stator and the out put from it to the switch box. garbage in garbage out. if the input to the switch box is ok and all the trigger inputs are ok and the blk/yellow wire is not grounded odds are you have a switchbox failure, the red stator actually seemed to work.

Re: mercury 90hp sport jet ,loss of spark at plugs

got engine running today!<br />put the old flywheel back on (one of the magnets is chipped).<br />the magnetic attration from flywheel to stator is much stronger on old flywheel.<br />could the new flywheel have duff magnets?or do i have a weak stator(don,t like to mention stator as every body says change it.)

Re: mercury 90hp sport jet ,loss of spark at plugs

I'm sorry I didn't see this sooner, I ended up in the hospital for a pulmonary embolism (It hurts like hell, and if it doesn't kill you, you'll just wish it did.)<br /><br />Anyway, Mark, I'm glad you got the engine to fire. I am by no means an expert on your engine, but one site that has been really helpful to me was built by a member of our community, KenImpZoom. Here is a link:<br /><br /> http://www.geocities.com/kenimpzoom/KensSeaRayder.html <br /><br />Ken has some great trouble shooting info on the electrical system. I'm sure he will trip over this post eventually, but I thought it would be helpful to you to see his information first.<br /><br />About your flywheel magnets, some have reported good luck in replacing chipped magnets by epoxying a new one in its place. Of course, you have to have a proper magnet to do so. If the chip is minor (a corner or edge, not cracked in half), I would just use the old flywheel, and tell them the new one doesn't seem to have the 'right stuff'. I doubt you have a weak stator.<br /><br />By the way, I have a son studying in London this term. He is impressed with the UK and grateful for the opportunity to visit and learn so much about your country.<br /><br />Good luck,<br />funpilot