1980 L6 90 HP mis fire

[zr_580_1994]

I got a 1980 6 cyl mercury with a strange mis fire . Thing will idle perfect all day long but rev it up at all and it mis fires bad . This thing has me stumped . Everything tests good. If I disconnect the red wire off the power pack the mis fire is gone . I can do this to either power pack and it will run fine I never tried running it with both unhooked . Compression is good everything checks out . Looking for suggestions on where to go from here . And what does the red wire do ?

 

[zr_580_1994]

I'm going to be posting 3 videos shorty but a small update . With voltage rectifier unhooked it runs perfect %110 I got nice spark in my in line tester almost purple . With one wire hooked up I got throttle response no more miss fire but it's lazy with both wires hooked up it miss fires Bad and have orange spark once reved up. at idle it's nice and purple . I changed rectifier with one off a running motor with no change in results . I also changed 8 inch of wire as it was rotten . I think I know what's strong but I'd like someone else to confirm

 

[zr_580_1994]

https://youtu.be/gl91obvKPeQ

https://youtu.be/1QZT8oUQ65Q

https://youtu.be/Ub8Obwxx678

I know it looks like it's misfiring in the video but it not it just the way my phone recorded it

 

[Chris1956]

Red wire from the switchboxes runs to the idle stabilizer? I would disconnect the idle stabilizer.

 

[zr_580_1994]

Red wire from the switchboxes runs to the idle stabilizer? I would disconnect the idle stabilizer.

The red wire I'm referring to is the ones coming off the Stator ?

 

[Chris1956]

You disconnected a stator wire, and the motor ran without a miss? Not sure why that would happen.

 

[zr_580_1994]

You disconnected a stator wire, and the motor ran without a miss? Not sure why that would happen.

I disconnected one red Stator wire off the power pack and the mis went away . However iv narrowed it down to this . It was never a mis fire but more of weak spark at high rpm . With the one red wire unhooked it ran better but not perfect .with both charge wires off the rectifier it runs perfect . Is it possible the Stator is no good so with charge wires disconnected all the power is getting directed to both power packs allowing it to get enough power to run properly ? With both charge wires connected my spark is nice and blue at idle but once reved up it goes orange and runs ****ty . With both charge wires unhooked my spark is nice and blue at any rpm and runs great

 

[Chris1956]

Maybe your rectifier is partially shorted, sucking the current out of the stator? Another guess on my part.

 

[stikboyy]

Sounds like you could have a couple of things going on. Your regulator rectifier could be on its way out as well as your stator. The red wires coming from the stator control the high speed spark(approx 2500 rpm and up) while the blue wires control the low speed spark. Are you disconnecting the red wires from the stator to the power packs or from the power packs to the voltage regulator?

Also see this link for detailed troubleshooting
http://www.cdielectronics.com/wp-content/uploads/2013/02/CDI Troubleshooting Guide - 2012.pdf

 

[zr_580_1994]

Sounds like you could have a couple of things going on. Your regulator rectifier could be on its way out as well as your stator. The red wires coming from the stator control the high speed spark(approx 2500 rpm and up) while the blue wires control the low speed spark. Are you disconnecting the red wires from the stator to the power packs or from the power packs to the voltage regulator?

Also see this link for detailed troubleshooting
http://www.cdielectronics.com/wp-content/uploads/2013/02/CDI Troubleshooting Guide - 2012.pdf

i disconnected the one red wire from the stator to the power pack.it ran better but not right. i should note i have figured out it was never a miss fire but it was just very poor spark at high rpm that made it sound like a missfire. i tried a new voltage regulator off a motor that i know is good and it is also brand new and it does the same thing. with it unhoked it runs perfect with it hooked it runs like garbage. what i dont understand is the charging coils and the ignition coils on the stator are seperate and it makes no sence why doing what im doing is having the effect it does .for the heck of it i disconnected the blue wire (low speed spark) and installed my inline spark tester same one thats in the above videos and once the high speed spark kicks in it is very very weak with the regulator hooked up.

 

[zr_580_1994]

Maybe your rectifier is partially shorted, sucking the current out of the stator? Another guess on my part.

i changed it with same result and it came off a good running motor and it was also brand new off that motor

 

[stikboyy]

The stator ignition and charging coils are indeed separate but the wires do overlap each other on the stator. It is possible that the high speed ignition wire is partially shorted to the charge coil wires. Check your stator wires for continuity to ground and for continuity between ignition wires and charging wires. If you get any result but an open circuit then the stator is the issue.

 

[zr_580_1994]

The stator ignition and charging coils are indeed separate but the wires do overlap each other on the stator. It is possible that the high speed ignition wire is partially shorted to the charge coil wires. Check your stator wires for continuity to ground and for continuity between ignition wires and charging wires. If you get any result but an open circuit then the stator is the issue.

I just wanted to report my findings .you where absolutely right . Between a charge wire and a red wire it zeroed my meter out meaning those wires are definitely shorted out inside the Stator .new Stator from Cdi electronics is on its way . I'm going to stick it in the water as is with the charge wires unhooked and try it this weekend.