My Mercruiser 3.0 stays in rerverse when lever moved to neutal?

yes, that is adjustable.

with the boat on land, motor off and key removed, place it in foward gear. go to the prop and turn it BACKWARDS.

you will hear a clicking sound as it turns. this is the engagement, popping in and out.

now go switch it into reverse, and turn the prop FOWARDS. again you should get the clicking. it should be equal in sound and feel to how it is in foward.

shift cables are mounted around the engine. i want to say on the exhaust, but i think thats only with the V motors.

there is one cable that goes to the controls, the other cable goes to the drive. you can adjust the length of either cable to get more foward or more reverse, but you need to ensure that the control cable allows the gear position switch to see the correct gear at the correct time.

you should focus on the cable that goes to the drive.

simply remove the cable, move the adjustment collar one way, place it back on and check the clicking. you probaly dont need more than a turn or three at most to get it where it should be.

BTW this is all something that should of been done before delivery. your boat was not properly rigged out.

dont be suprised if you find more problems further down the line.

Check if the shift interrupter works, adjust the switch lever to activate at 1/4" of lever movement while centered in the Y.

Could be adjustment or bad cable, control box loose screws. There is an adjustment on the engine that has to be in neutral for the micro switch or it won't shift properly.