Tohatsu M50D Wiring Question

[sumnerrt]

All,

I am in the process of putting an auto mixing system back on my M50D motor that the previous owner took off. I am 99% complete and today when I took off the plastic cover that covers the wires, CD unit, etc looking where to connect the lime green wire Fromm the oil level sensor on the tank (I found it) I took a close look at all the wires underneath because the electrical tape was all gunned up and I took it all off. I noticed that there were two short black/yellow wires that on the diagram on the inside of the cover show should be connected together but they were disconnected and taped up. My questions follow:
1. should they be connected like the diagram shows (I'm assuming so but it was running fine with them disconnected)
2. Why would they be disconnected?
3. The black wire coming off the sensor for the oil tank looks like a ground wire but I can't find on any diagrams where it actually goes.......can I just ground it using the bolts for the oil pump?
4. Before I get bombarded with buy the manual, etc. I DID, it's on the way, but this is a forum and I'm not looking for advice on buying the service manual like I read in so many other posts, don't bother.

I have saved a ton of money buy ordering parts online by referencing the parts manual, eBay, etc and pretty proud of myself because although the motor ran, it ran rough unless it had brand new spark plugs in it. Service tech told me about how the 50 to 1 ratio is for wide open and at low speeds causes excessive oil and quicker fouling. I also am concerned about low water flow when running and only this last weekend did the buzzer ever go off so I ordered the water pump kit and I pulled the thermostat to check for sand (I ran up on a sand bar) only to find out it didn't have one and after reading the posts by the guru and some others I immediately ordered one of those and a gasket. Brothers,, looking for some friendly assistance, so help if you can. I have questions about conveying from mixed fuel to the auto mixing system for the first time but I'm hoping "it's in the manual" I so often read holds true.

 

[pvanv]

Re: Tohatsu M50D Wiring Question

Yes, black is ground. Grounding the sensor wire triggers the alarm.

 

[sumnerrt]

Re: Tohatsu M50D Wiring Question

I found this response on another website (www.marineengine.com) which answers the question about the black/yellow wires. I'm assuming that the previous owner disconnected the wires to prevent the alarm from going off when he disabled/took off the automixing system for whatever reason but since I am reinstalling it....

1. I am reattaching the black/yellow wires
2. Based on Pauls commenst (thanks) I am grounding the wire from the oild sensor from the oil tank using a bolt from the oil pump and routing the wires along the bottome out of the way and making sure they dont get caught in any linkages
3. I am using tiny zip strips to replace all the nasty/stick electrical tape to keep everything neat and out of the way.

any thoughts?

post from marineengine.com
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The CDI unit has a wire Clymer says is black/yellow but my engine had a different colors. This wire is short with a pull apart connector that comes out of and goes back into the CDI unit. If you pull apart the connector to open the connection it will disable all the engine safety functions and you can test if the engine will run over half speed for a short time. If the engine runs OK it is a sensor problem or a bigger problem the sensor is detecting. Your problem may be with the oil level sensor. You may have to disconnect the sensor wire at the CD unit."