Can't turn the motor off

[1970skier]

Help. I bought my first MC last year in October. It's a 1989 MC prostar 190 last year with 320 hours and new engine, last year. I took it out the second time this year and could not turn the motor off. The key turns in all positions but would not turn it off. Also the kill switch would not work, and had no affect. I eventually disconnected the positive cable from the battery to stop the engine.
Any ideas what is causing this? I have read various threads that say a bad ground somewhere or a bad switch. If the switch was bad why did the kill switch have no affect?
ANy help is greatly appreciated. Also, where do folks get parts for this year and model?

[d2jp]

Hey 1970,
Forgot to mention in my PM that you may have a bad ignition switch. And as I mentioned your kill switch has probably been bypassed and that is why it’s not stopping the engine. Discount inboard marine www.skidim.com has replacement ignition switches and good tech support too.
Hopefully waterlogged or someone will chime in here for more info and/or how to check your ignition switch!

[1970skier]

Thanks. I cleaned the engine ground and it worked (for 2 more trips) then would not turn off again. The kill switch had been bypassed. I took the dash plate out and physically separated the kill wires to no effect. I disconnected the pos and neg battery terminals and the boat still ran! Finally, I pulled the distributor cap wire (got a good shock) and that killed the motor. I ended up replacing the ignition switch and disconnected the coil wire from the starter relay/Solenoid. I have electronic ignition with no ballast resistor so this wire was superfluous. I have had no problems since.

[88 PS190]

Good you got that sorted. So do you think the culprit was the ignition switch or the wiring from whoever bypassed the ballast resistor?

[waterlogged882]

. and disconnected the coil wire from the starter relay/Solenoid. I have electronic ignition with no ballast resistor so this wire was superfluous. I have had no problems since.

^ ^ this ^ ^

Coil wire (typically purple) goes straight to the ignition switch. The only thing ignition related on the relay (aside from the hot battery) is the neutral safety switch wire from the transmission.

.

[Huckelfin]

Wow this is super sketchy. Instead of getting shocked, I would think that disconnecting your throttle cable and turning idle down as far as possible would choke the engine out and cause it to die. If that doesn't work, do that in combination with blocking the carb inlet to stop airflow.