Tilt/Trim - Reverse Lock Control Knob

[AltheaToldMe]

Can someone explain to me what this is and how it is properly used. I have checked the Seloc manual and nothing is really mentioned about it (that I can find.)

I'm curious if I have to change the settings for any reason.

Thanks.

 

[Chris1956]

Re: Tilt/Trim - Reverse Lock Control Knob

Are you asking about the black knurled knob on the control valve of the PTT Pump, that is mounted in your boat? If so, when turned all the way CW, it should allow you to manually tilt your motor. It will not allow a "power tilted" engine return to the down position, however.

 

[jimmbo]

Re: Tilt/Trim - Reverse Lock Control Knob

WHile it will allow the engine to tilt up, it is not supposed to allow the engine to lower regardless of how it was tilted up, power or by hand. Opening the bleed screws to bleed the oil is the only way to get the motor down manually.

 

[Chris1956]

Re: Tilt/Trim - Reverse Lock Control Knob

Hey Jimmbo, That has not been my experience. If I opened the manual release and tilted the OB up by hand, I could lower it as well by hand. At least on my '77 Merc 1500.

 

[jimmbo]

Re: Tilt/Trim - Reverse Lock Control Knob

Hey Chris, I was just just quoting what I saw in the Merc Service Manual. Maybe your unit was defective. I never had to tilt my 78 90hp by hand but I do remember a neighbor letting the oil out of the rams get his 77 85hp down.

 

[Chris1956]

Re: Tilt/Trim - Reverse Lock Control Knob

Jimmbo, It is true that if the motor is "pumped up" using the PTT. you would need to crack the lines to let it down.

BTW - My PTT was not defective, as it was nearly new when I got it, aqnd my owners manual confirmed it operated properly.

 

[Rapanui47]

Sorry to pick up this old tread,but it heat home with me.
My 50 HP Mercury Outboard circa 1983, has separate Prestolite 105921 PTT pump unit installed inside the boat.
Speaking of this black knob you suppose to turn CW to disengage reverse lock or CCW to engage it. Mine just simply screwed onto some treaded post and do not rotate anything. So by turning it CCW I can completely unscrew it from this post. This post is the part of 1/2 inch nut like head, screwed into the nod of control block. When taken of inside is some sort of piston, which can be pushed by hand, but as far as I can see rotation of the know hason effect on this internal.
Am I missing something?
Can somebody she'd the light, please.

Had to correct last paragraph.
Size of the nut head is 3/4 inch and rotation of the knob has no effect on position of internal piston.