Tilt Trim 1977 115hp Mercury trim motor spins only

115merc

Recruit
Joined
Jul 18, 2003
Messages
3
Wanted to take boat out first time this year. Bought last year worked great. Kept covered mild OR winter no freeze. Released travel clip motor came down. Could not raise motor back up with tilt control or by hand. Turned disengage screw clockwise no help. Removed drain plug oil foamy on top and very low and under pressure (squirted). Both springs had some varnish like deposits. End stop (looks like a nail without point)and ball bearing clean enough. Cleaned springs fill with oil and bled by raising and lowering motor by hand (don't know best method). Put back together engaged knob CCW. Sellenoid relay clicks & motor runs but tilt does not move up or down (as before). Rechecked oil level. Can move up and down by hand now. Suspect check valve type issue. Can take apart if had technical documents. Thanks, it don't look like I will be able to take it camping this weekend. Is it possible to manually lockdown motor with pin. Holes and locking mechanism present but unused. Can I add a pin so that I can use boat temporarily at mid speed & careful reverse. My luck.
 

sag2

Seaman Apprentice
Joined
Jun 25, 2002
Messages
33
Re: Tilt Trim 1977 115hp Mercury trim motor spins only

If you can manually lift the motor, you should be able to run it with a tilt pin installed. Make one out of a long bolt of the proper diameter. Use a ny-lock nut to keep bolt from falling out. Use two bolts and nuts (one on each side) if you can't find one bolt of the proper length. If you use two, be sure they are good and tight.<br />Go easy in reverse, as the motor will want to come up.
 

115merc

Recruit
Joined
Jul 18, 2003
Messages
3
Re: Tilt Trim 1977 115hp Mercury trim motor spins only

Thanks a bunch. I just looked again to see if there were any numbers on the pump/motor. All I could find was SAE J1171 on the motor. I think this is original equipment in a 1977 16' low profile Jetster. There is a tag that talks about the engage/disengage knob and the SAE 10w30 or 10w40 oil to use, also to fill to bottom of threads. There must be a problem in the pump, so I am going to need to find a book on it and a rebuild kit.
 

banditt83

Recruit
Joined
Jun 19, 2007
Messages
4
Re: Tilt Trim 1977 115hp Mercury trim motor spins only

Good Luck I Have A 1982 And The Parts I Need For My Trim Motor Are Discontinued. Try Browns Point Marine On Web. They Have A Good Parts Cataloge.
 

gejandsons

Petty Officer 2nd Class
Joined
Sep 11, 2003
Messages
134
Re: Tilt Trim 1977 115hp Mercury trim motor spins only

When you fill it with oil you will probably have to cycle it from down to up & back several times to get all the air worked out. Those pumps won't pump air. Cycling works the air out.
Good luck.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,103
Re: Tilt Trim 1977 115hp Mercury trim motor spins only

115Merc, Those PTT units are not self bleeding. Also the control valve is not rebuildable. If the motor sounds like it is running free, you likely have air in the unit. There are two bleed screws on each cylinder. The bleed screw on the top, next to the grease fitting bleeds the trim cylinder in the down position. Open it and run the pump and watch the oil spray up. When no more bubbles, it is bled. Repeat for the other side. Now, remove the trim cylinders and turn them around and face the inside where the lines attach, up. Remove the "up" bleed screw next to the lines. Run the pump and watch the oil spray up. When no more bubbles, the unit is bled. Repeat for the other cylinder. The motor is self bleeding, leave the fill screw a bit loose, while bleeding the cylinders.
 
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