Motor raises up when in reverse

79Merc175

Cadet
Joined
Aug 7, 2006
Messages
27
I've got a 1979 Merc v175 that I recently inherited and recently noticed that when I give it throttle in reverse- the motor starts to rise up and seem to not be "locked" down as it should and then will lower back down as I decrease throttle. Any ideas on why this may be happening? Please help.
 

Plainsman

Rear Admiral
Joined
Apr 2, 2006
Messages
4,062
Re: Motor raises up when in reverse

Does the Tilt and Trim work? Or do you lower and raise it manually?
 

Plainsman

Rear Admiral
Joined
Apr 2, 2006
Messages
4,062
Re: Motor raises up when in reverse

Does the pump have a reverse lock?
 

79Merc175

Cadet
Joined
Aug 7, 2006
Messages
27
Re: Motor raises up when in reverse

that i dont know, how would you be able to tell? if i look at the pump, what would it look like?
 

papasmurf

Petty Officer 2nd Class
Joined
Nov 9, 2004
Messages
181
Re: Motor raises up when in reverse

79merc175 said:
that i dont know, how would you be able to tell? if i look at the pump, what would it look like?
 

papasmurf

Petty Officer 2nd Class
Joined
Nov 9, 2004
Messages
181
Re: Motor raises up when in reverse

Do you have a serial # for this motor?
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,102
Re: Motor raises up when in reverse

79Merc, If you have a knurled knob on the PTT Pump, it needs to be turned to the locked position to keep the motor from lifting up in reverse. I think you need to turn it CCW???? Id should say in the owners manual as well as be printed on the pump.
 

79Merc175

Cadet
Joined
Aug 7, 2006
Messages
27
Re: Motor raises up when in reverse

Thanks Chris, I dont actually have an owners manual but i'll try to locate this knob when I have her out this weekend.

One question though, would this be the same as the manual release for the tilt/trim? if so, I would think that if this were open that i wouldn't be able to have the motor tilt up and stay up for trailering.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,102
Re: Motor raises up when in reverse

79 merc, It is the same as the manual release. The book says that if the T/T release knob is in the release position, the motor can be tilted up by hand. It also says that if it is then tilted using the PTT system, it will stay up. It would seem your observations are consistent with it intended operation.d:)
 
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