Re: 1986 mariner 150 alarms
I have an 88 Mariner 150 that does the same thing. It seems to happen when you fire it up cold - stops as the motor gets warm - but I'm really not positive as to what it actually means.
EDIT: Doing some reading, it appears the alarm is a low oil alarm. I keep an eye on mine and I know it's not out of oil - main tank in the o/b housing is full to the brim - but the reservoir in the boat might be low. I'll look at mine, may be something to check on yours.
EDIT X2: Wrong on my part. The solid beep is an overheat alarm, not an oil alarm (which would be intermittent beep beep beeping). I just replaced the water pump impeller and all gaskets, etc. in mine and the motor pees fine, also practically sucks the water hose dry when it's running on muffs. I'd advise you to do what I'm going to do with mine: Inspect the temperature sensors, thermostats, and all the wiring related to that hardware.
To answer your second question, you can buy a delete kit for the oil injection system.
