older merc 90 tilt trim thumscrew control knob.

[stevehendo34]

What is the thumb screw, (control nob), you can turn with you fingers do on the tilt trim pump inside the boat.

The manual says it is the control nob but dose not say anything about what it is for.

I guess the other thing is what dose the control valve assembly it self accomplish?

 

[Chris1956]

Re: older merc 90 tilt trim thumscrew control knob.

That is the manual release for the PTT unit. If you turn it all the way CW (I think its CW), yu can lift and lower the motor by hand. If the motor is already titled up under PTT, this knob will not release it.

 

[stevehendo34]

Re: older merc 90 tilt trim thumscrew control knob.

So how and were do I set the Knob for normal use.

 

[Alumarine]

Re: older merc 90 tilt trim thumscrew control knob.

For my 82 merc 50 the manual says.

Turn knob fully clockwise to raise motor up manually.

Normal position is fully counter clockwise.

To lower motor manually you must open one of the small diameter hoses.

 

[Chris1956]

Re: older merc 90 tilt trim thumscrew control knob.

I think the smaller hoses are for up. To allow the motor to go down, open one of the larget hoses. Oil will spray everywhere.

 

[Alumarine]

Re: older merc 90 tilt trim thumscrew control knob.

I was going by what the manual says.

I think the smaller hoses are for up. To allow the motor to go down, open one of the larget hoses. Oil will spray everywhere.