Mercury Sport Jet 175 won't start

[MTR_1988]

Hey everyone,
I'm new to the group and just purchased my first boat this year. It has the 2-stroke 1998 Mercury Sport Jet 175. Did have it running out on the water when I first got it, both when I purchased it and after when I got it home. The last time when we brought it back in there was a bad miss. Looked it over and found a plug wire broke, then others weren't clipped on right. Ended up getting new wires and plugs. Did an oil injection delete too, the plastic gear was on it's way out and I grounded out the oil level sensor. Also replaced the engine temp sensor because it stopped working. Did a bunch of other stuff in the meantime, maintenance and personalization. Getting it ready to put back in the water after sitting for a couple months and now it won't start. It has spark, plugs are wet with fuel and compression on the one cylinder is 113psi when it's cold. Fuel pump does work, however there's low voltage at the enrichment solenoid. I have put 12v to the valve and it works fine. When I first tested the voltage it was around 11, then dropped to 10, and now in the 9 range. Battery is charged up, I've checked the engine grounds, cleaned the terminal going to the ecu, and did resistance test between the ecu plug and the solenoid, checked out good. Not sure what I'm missing here, I did go around with DeoxIT terminal protectant/cleaner on any exposed terminals too. There is a primer bulb someone installed, I gave it a couple squeezes before and it started up. Not sure if it's enough or I should be squeezing it more. I have also drained the fuel tank and added new fuel. Any help is greatly appreciated.

 

[MTR_1988]

So I've discovered it's the black/yellow wire causing the issue. I disconnected it and the engine fired right up. What would cause this? Short, faulty ignition switch, ECU?

 

[MTR_1988]

I've isolated it to the one switch box. I tested the wires with a multimeter and the one causing the issue was almost 4k ohms. Anyone ever had a switch box cause this? Looking at switch boxes, the version for my engine is like 4x the price because it's sealed. Would it be okay to use the one made for the outboards instead? I know the connectors are different, I can make wiring for that.

 

[Sportjet175]

I've isolated it to the one switch box. I tested the wires with a multimeter and the one causing the issue was almost 4k ohms. Anyone ever had a switch box cause this? Looking at switch boxes, the version for my engine is like 4x the price because it's sealed. Would it be okay to use the one made for the outboards instead? I know the connectors are different, I can make wiring for that.

Thank you for updating your findings even though you have not gotten a reply. I am not sure what the issue is, but am curious to know what is causing it. I have heard of the magnets on the flywheel causing run issues as well, I have a 2003 175 SJ that won't idle when warm. With regards to yours how did you check the gear/pump condition for the auto 2 stroke oil injector?

Thanks again