83 mariner 115hp Help! won't start

[dannelle]

Hi, I am in desperate need for help on this thing! I have an 83 mercury mariner 115 HP I-6. We bought this boat and it ran for a few months before we started having problems. First it started with the trim pump and we got that repaired and then from there it has been nothing but a mess. Who ever we got it from first hot wired the engine from the shifter (is that the control box) to the engine and it caught fire. We replaced the wires and have them now to where that is ok. I do plan on getting a new wiring harness and shifter once we get this thing fully running. From there everything else started to fall apart. Come to find out at one point in the boats life the starter shorted out and changed polarities. So instead if replaces such starter they just swapped the battery cables. And the taped them to look like they were correct. Once we found that out we replaced the started and correctly placed the battery cables to where they should be. Because of this we have replaced the rectifier as well. It still would not start. We then turned to the stator and have replaced that...nothing! So yesterday we replaced the switchboxes. And again nothing! It sounds like it wants to start but it just won't fire up. I am at a total loss as to what is the problem. We had the plug wires checked to make sure that was not the issue and they said they were fine.

One other thing. As far as the plug wires go do they go in any specific order on these engines because they have been wired
1 to 1 2 to 2 3 to 3 4 to 4 and so on . Where as someone said that there is a firing order and he believes but doesn't know for sure that they should be set in the firing order. Which I believe but could be wrong bc I am not standing by it but I thing 1-4-5 2-3-6. Are the wires suppose to go in that order or what. I am trying to avoid the ridiculous costs is a shop so all comments are welcome! Thanks.

 

[Chris1956]

Re: 83 mariner 115hp Help! won't start

Danelle, That motor should have a permanent magnet starter on it. If the magnet is installed upside down, the starter spins the wrong way. Maybe your old starter was put together wrong.

Put a timing light on each spark plug wire and crank her and see if you have spark to all 6. Firing order will be determined by the placement of the stator and trigger wires on the switchboxes and the coils. I recommend you get a service manual to make sure they are correct. I do not have a wiring diaghram for your motor, but on similar V6 motors, which share your ign system, they band together the stator wires that go on a particular switch box (the outer one), so they do not get mixed up. On on one of your switchboxes, you may see 4 stator wires banded together in two groups, and three switchbox to coil wires banded together for coils 2,4,6. The wires on coils 1,3,5 are unbanded on the V6 motors. Hope that helps

 

[Charlie61]

Re: 83 mariner 115hp Help! won't start

this may help, my plugs where numbers going too coiles hope the help