merc 115 2 stroke - no spark

[johnntab]

I hooked up the battery terminals wrong on my boat and now it wont start. I did not immediately notice the problem. The engine is a 2004 merc 115 2 stroke. I hooked up one of the black cables running to the fuse box on the boat to the positive battery terminal. When I went to start it today to go to the lake, nothing happened, It would not even crank.
That is when I noticed the problem. I had hooked the wires up wrong and melted what appears to be a ground wire that runs to the gauges and switches on the boat.
When I hook up correctly, the engine will now crank, but I cant get it to start. I tried to test for spark, but I am not sure if all cylinders of this motor should have spark at startup or idle. It apparently runs on 2 of the 4 cylinders at idle. I checked the middle two cylinders and did not find any spark.
Which cylinders should be firing at idle?
Could the kill switch be the problem? I am not sure how the kill switch prevents the engine from running even though it can still crank, so I thought that may be a possible answer.
What else should I be looking for?
Is there some way to bypass the wiring going to the boat, and just attach the battery leads on the outboard to see if the problem is in the boat or the outboard?
I am going to start replacing the melted wire and any fuses tomorrow, as well as making sure to label the wires appropriately.
I have looked for a manual for the engine, but cant find one to buy right now. I am still looking for a manual available to buy.
Thanks

 

[johnntab]

Re: merc 115 2 stroke - no spark

I have done some further investigation, and talked to a service center, they think the problem is in the kill circuit. If I unhook the kill circuit (black w/yellow wire), the engine will start. I plan to rewire the entire kill circuit and replace any other damaged wire. I will post the repair/anser when available.
thanks

 

[johnntab]

Re: merc 115 2 stroke - no spark

I have tracked down what appears to be the problem. I have rewired the entire ground circuit of the dash/console, and in doing so, i found that the ground wire to the ignition is likely the problem.
I still dont have power to any accessories, lights, bilge pump, etc. but I will continue to work on wiring issues.
When I did get the engine to start, there was no water coming out of the tell tale pee hole. I used a weed wacker string to open it up, and now the engine is fine. I still have to leave the kill switch wire unhooked in the engine until I replace the key switch though.
Hopefully, this may help someone else who makes the same foolish mistake as I did.