No spark on one of my MR1 on yamaha230SR

[rollcall129]

I’m new to the forum so be gentle! I surfed the site looking for info but couldn’t find or overlooked what I seek.

One of my 140 hp motors have no spark in any one of the 4 plugs. The wires trace back into a black box before the coils which I assume all the electrical for the boat originates. The bolts that hold the cover on just turn and I can’t remove the cover. Really don’t want to pull my boat out and bring it to mechanic.

Looking for some guidance.
Thanks in advance

 

[Gym]

That black box is the ECU (engine control unit). There is a round cap on the front. unscrew the round cap and check the fuse. There is a fuse puller and a spare fuse inside the cover.

 

[Gym]

If the fuse is good you may possibly have a bad ECU. To remove it you need to get on both sides of the back engine wall to remove the bolts that hold the ECU to the partition. What were you doing when this engine quit?

 

[rollcall129]

I checked that as well. Fuses are good. I was told that probably not the coils because it would be extremely rare that both coils would fail and all 4 plugs not spark. So would have to be before the coils and the wires feed into that black box, About the size of small briefcase, attached to the transom.

 

[rollcall129]

I wish I were home to take pics for ya

 

[rollcall129]

Just took out of storage. Motor would turn but not run. I limped to the dock with the good motor.
Half way there I put the boat in neutral for giggles to try the other motor again. After about 30 seconds it fired up. I ran it for about 30 seconds around 4-5000 rpm then a little higher for about 30 seconds to try and burn off the fog. Then it sounded almost like an engine backfire and engine cut out. Wouldn’t start again.

 

[rollcall129]

how do I get that box off. Get back there with a wrench to hold the nut. I tried getting into the access port in the storage compartment but it’s way to far to reach the furthest bolt. Do I have to cut a hole?!?

 

[rollcall129]

I think my buddy at the house just figured it out. Have to go thru the clean out port on the other side of the transom.

 

[rollcall129]

 

[Scottintexas]

Aren't you jumping way down the trouble shooting list by going to the ecu???
I would by pass your safety switches first

 

[Gym]

@Scottintexas is correct. Your safety switch by the throttles controlls the ignition to both engines. If one engine fires and the other doesn't try holding that plunger switch up higher while trying to start. Sometimes the plastic lanyard clip wears and doesn't hold the switch up high enough. I've had to wrap electrical tape around the clip on a friends boat for that exact problem.

 

[rollcall129]

I’ll be at it again tomorrow. I will ask him if we can check that. I’m somewhat illiterate when it comes to electrical systems. Im not gonna even pretend to be literate when it comes to any of it but I learned a lot yesterday and today. I do appreciate all the advice.
Thanks guys. I’ll keep ya posted.