1985 Mariner 115 inline six no spark

Hello all. I just today picked up this bass boat for the trailer and the engine. I did a compression test before I bought the rig and it read 120 or so across all 6. I had to bring my own battery. I got it home and thought I'd put the battery back in and see if it would fire. I put gas to it and I'm getting no spark at all. I know its getting gas cause it is coming out the carbs and I took a plug out and it was drenched. The choke does not engage on the controls. There is allot of wires in the battery box and I have one red and the main pos hooked up then the main ground and there was three wires wrapped in tape that said ground. the engine cranks with just the main ground and the main pos. I know its a long shot here without seeing it but taking the shot anyway. Thanks, Chris

Re: 1985 Mariner 115 inline six no spark

outboardignition .com has test procedures for outboards.
Usually there is only 2 wires that are needed for the outboard.Possible the trim/tilt will have it's own leads.
All others on a bass boat could be leads for a charger or a trolling motor.J

Re: 1985 Mariner 115 inline six no spark

OK, thanks I'll check that out.

Re: 1985 Mariner 115 inline six no spark

Look at the switch boxes..the yellow and black wire goes to each switch box. there is a mercury switch, a little round unit that cuts off the spark when the motor is tilted...these go bad and you don't need it...keep in mind that you will have one blk/yellow wire on each switch box which is the kill wire...you can also disconnect both of these to see if you get spark.. if you do, you have a bad key switch or harness... you won't be able to stop the motor if it starts so be prepared to pull fuel line... after doing both of these and still no spark, I would spec out the stator...you very rarely lose two switch boxes at one time however Merc recommends changing both at the same time...good luck

Re: 1985 Mariner 115 inline six no spark

OK thanks much. I'll get back at it after work if it isn't raining and try. I'm almost thinking it is the key switch since they had wires unhooked and when the two that they had unhooked are hooked up they blow the fuse on the engine when you push in the choke.

Re: 1985 Mariner 115 inline six no spark

OK pulled the two wires off the switch boxes, black/yellow and no spark. read to pull one at a time so did that no spark, read to unhook the rectifier did that no spark. Seems like I'm just getting power back to the starter solenoid and the trim solenoids. choke blows the fuse when engaged and I don't have the equipment to test the stator. Again, when I looked in the throttle box the first time they had left two wires off the ignition switch for a reason. the yellow/black and the black. after hooking them back up and blowing fuses I figured that's why they did that. There was also another kill switch mounted next to the remote control with a lanyard on it. something fishy here.

Re: 1985 Mariner 115 inline six no spark

The wiring is just one of your problems.

The yellow w/black may be the choke wire, look at the choke solenoid on the motor to check the color there.

The solid black should be ground.

Getting back to the 'no spark', at the motor, disconnecting the black w/yellow trace linking the switchboxes to the motor wiring harness disconnects the 'ground-to-kill', if the ignition system is functioning, there will not be any means of shutting it off, so do not start the motor, only check for spark.

Remove all the spark plugs, this will save wear and tear on the starter and battery.

Plug all the spark plugs back into there wires and tape the metal bodies together along with a wire that you can attach to a good ground. This will help prevent any stray sparks from igniting fuel fumes and also protect the ignition from errant currents.

Recheck for spark, remembering that there is a minimum cranking speed of 300 RPM for the stator to generate sufficient voltage to operate the ignition. A well charged battery and good, clean, tight cable connections are required.

Re: 1985 Mariner 115 inline six no spark

what I did today. I had a outboard mechanic on the phone with me and we unhooked the harness from the block and unhooked the two kill switch wires from the switch box and jumped to start from the solenoid. No spark. I unhooked the two yellow wires from the rectifier that go to the stator and still nothing. I put it all back together except for the two yellow black mercury switch wires and charged the battery, hooked my timing light up to the number one plug, turned the key and after a couple cranks came spark. same with plug two and three. 4/5/6/ have no spark yet. Is there a way to test the switch box? Also why after removing wires and wiggling wires I all of a sudden got fire to the top switch box.

Re: 1985 Mariner 115 inline six no spark

New update. Turns out maybe it wasn't cranking fast enough when I unhooked the kill wires at first cause I got it running tonight. Hooked the kill wires back up and took the ends off the key switch and put them on a toggle switch and now I can start it and turn it off with the key. One problem is I'm only getting spark on one plug on the bottom switch box. I can't believe how smooth it runs out for only hitting on 4 cylinders. Will a switch box just let one hit or is it the two coils? I'll do a test on them tomorrow. Thanks for all the help and I just wanted to keep updated in case some one else has similar problems.