75 Hp was running great died and would not start ??? Need help

[truhl_58]

1075716 MERCURY 1986 75 OA994493

Started right up on the muffs in the driveway and idled perfect. Took it to the lake fired right up idled great, ran it accross the lake WOT for 5 min. idled down and trolled for about an hour never missed a lick, started to make a left hand turn and it died. Tried to restart no luck never fired once (electricial ??). Towed the boat to the ramp and hauled it to the shop. The boat sat at the shop for two days where he charged the battery (low from trying to restart at the lake). The moter started right up and idled perfect. Does anyone have an idea or is there a common problem with this model engine ?? I was not able to check for spark in the lake but it acted like it was ignition I think???

 

[86 century]

Re: 75 Hp was running great died and would not start ??? Need help

Could be anything from a pluged tank vent to the stator heting hot and braking down.

Real tough to tell with out checking things out.

Run it on the muffs for a wile to see if you can get it duplicate the failer.

 

[cr2k]

Re: 75 Hp was running great died and would not start ??? Need help

While running jiggle all the all the wires and connections too, may have worn insulation causing a short or a bad wire plug somewhere.

 

[1nebel0]

Re: 75 Hp was running great died and would not start ??? Need help

If you have a mercury switch(little blk switch on the ignition plate) disconnect it as these can go bad and cause intermittant spark..They were designed to prevent you from starting the motor in the tilted position..you don't need it.....not saying this is the cause but one less thing to go wrong..have had a couple go bad..

 

[aussieflash]

Re: 75 Hp was running great died and would not start ??? Need help

Did the guy at the shop check it out,or just charged the battery?
Do you have temp gauge or overheat warning?Possible you overheated?
Check compression wet and dry.Check fuel lines,pump and tank.Make sure water pump/impeller is cooling properly.

 

[truhl_58]

Re: 75 Hp was running great died and would not start ??? Need help

The shop charged the battery and it started right up and idled fine, not broke so he can't fix it. No temp gauge but it was a COLD day, cold water had good flow from the pee hole, new water pump. New fuel line, rebuilt fuel pump, and new plugs. Tank vent was open I don't think it was fuel it didn't spudder it just died and would not fire again not at all cranked it over till it pulled down the battery that is why the shop had to charge it. I think I am going to start with all the electrical connections, and try to find that mercury switch and eliminate it then run it with the muffs and see if it will fail again.

 

[truhl_58]

Re: 75 Hp was running great died and would not start ??? Need help

Brought the boat home from shop and did a little looking around for myself. Found some green corosion on a pair of wires between a diode and the stator. See pics.Should I replace the stator ? Should I try to repair the wires ? Would these wires even have anything to do with the motor dying and not restarting anyway ?

 

[brandon110]

Re: 75 Hp was running great died and would not start ??? Need help

those wires would have a lot to do with not charging the battery. you need to replace the stator. looks to me like they got hot you need to try to find out why that would of happend. im sure replacing you stator will fix your problem. those could of grounded out real easy or chances are it looks like that inside the stator too. looks like you have a black stator so when you replace you will most likley need a red stator kit. its an update as to the black stators where very problematic. and added tip loosen the nut on the yellow start wire on your starter and turn it down so its not at a 90 degree angle that will cause problems for you at some point.

 

[truhl_58]

Re: 75 Hp was running great died and would not start ??? Need help

Ok if I need to change the stator, should I change the trigger assembly since I have to pull the flywheel anyway? I am not looking to throw money away but I am getting tired of being towed in and it looks like while I am so close now would be the time. And could the voltage regulator cause the wires to have gotten hot and should I replace as well? Thanks for all the info and help.

 

[brandon110]

Re: 75 Hp was running great died and would not start ??? Need help

i wouldnt worrie about the trigger but i would inspect it and test it since it will be right there. i would buy a new rectifier the thing the 2 yellow wires hook to and when you get it all back together put a voltage meter on your battery and check to make sure it is charging.

 

[phebus1]

Re: 75 Hp was running great died and would not start ??? Need help

The insulation on the old wiring is prone to breaking down. That is what you are seeing, and then the exposed wires corroding. For some reason, the old yellow insulation seems to be the worst.
I would replace the stator and the rectifier as noted.

 

[truhl_58]

Re: 75 Hp was running great died and would not start ??? Need help

Is there a better brand say CDI or Mallory or Sierra or??? even better is there a brand to stay away from ? Also is it the 1-1/2" 16 tpi puller I need to pull the flyweel off ?

 

[brandon110]

Re: 75 Hp was running great died and would not start ??? Need help

go with mercury parts if you want aftermarket id use cdi they have good quailty stuff.

 

[truhl_58]

Re: 75 Hp was running great died and would not start ??? Need help


Here are some pics of what I found. Someone hid the bad wires under electrical tape. I put it back together, charged the battery, pumped up the bulb and it didn't turn more than a turn and it started right up. Idled great ran for 10 min no problems for some reason it didn't seem as cold natured as before. I know these wires are for the charging but if they shorted together would it cause the motor to die? Do these wires do more than charge the battery ?