mercury 1980 115 only firing on 2,4,6 none 1,3,5

[johnny09]

Hello,<br /><br /> I have a 1980 mercury outboard 115. I took it out for the first time this year last weekend. saturday it ran perfect, no problems, but on sunday it had a miss and would not plane out. I checked my firing and found that only the 2,4,6 cylinders were firng and the 1,3,5 were not. it has me stumped because it has 2 coils and 1,2,3 are on one coil and 4,5,6 are on the other. Please help!! thanks

 

[Clams Canino]

Re: mercury 1980 115 only firing on 2,4,6 none 1,3,5

It has two SWITCHBOXES and one coil for each cylinder. <br /><br />Ohm out the stator as per the manual then test the trigger. The switchboxes interact to some degree so a bad switcbox could be the problem too.<br /><br />You can rule out the stator and trigger with static tests. That just leaves you with the two switchboxes.<br /><br />Remove the black and white bias wire between the two boxes and test spark again too. See if that doesn't limit the interaction and leave one switchbox standing as the culprit.<br /><br />-W

 

[johnny09]

Re: mercury 1980 115 only firing on 2,4,6 none 1,3,5

thanks alot for that info, i am a boat idiot and this will really help. I will try this and let you know, thanks alot for the info!!

 

[KCLOST]

Re: mercury 1980 115 only firing on 2,4,6 none 1,3,5

Clams, I'm having a similar problem...<br /><br />What does removing the black and white bias wire do?

 

[mellowyellow]

Re: mercury 1980 115 only firing on 2,4,6 none 1,3,5

swap the switches and see if problem follows.<br />good luck,<br />M.Y.

 

[Clams Canino]

Re: mercury 1980 115 only firing on 2,4,6 none 1,3,5

Originally posted by KCLOST:<br />Clams, I'm having a similar problem...<br /><br />What does removing the black and white bias wire do?

Eliminates some of the interaction between the two boxes. A usefull troubleshooting tool sometimes, but don't run it that way for real.<br /><br />Like Mellow said - swapping the boxes helps too. Mercury recomends replacing them as a pair, but if you get lucky, you can get away with just one.<br /><br />-W