Power tilt/trim Reverse & Stumps question

tbarr106

Recruit
Joined
Jul 20, 2004
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5
hi <br />i have a 1976 115hp merc inline 6 <br /><br />im adding a power tilt/trim system <br /><br />what my is question how does the Hydraulic<br />pump and rams react when you hit a stump ?....<br /><br />and how do they react in reverse ?....<br /><br />im new to power trim and dont want to scew up my Transom or lower unit !.....<br /><br />my pump has a reverse lock knob what and how does it function ? (trailering i believe )....<br /><br />any advice and expertize or links is welcome<br /><br />im installing the trim unit wiring and refurbishing my deck boat myself <br />so as you can see im very mechanically inclined.....<br /><br />so please feel free to get into detail about system ......<br /><br />which is the merc 4 port round mtr pump<br />single Solenoid type (Why did they add a second )<br />2 rams and 3 button trim switch Up /down/up-out<br /><br /><br />thanks
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Power tilt/trim Reverse & Stumps question

watermark.php
<br /><br />Hope this helps.<br /><br />Chris.............
 

tbarr106

Recruit
Joined
Jul 20, 2004
Messages
5
Re: Power tilt/trim Reverse & Stumps question

ok great this a great diagram <br />i see item J is a impact relief valve <br /><br />how does this function when you hit a stump <br /><br />1100 psi to 150 psi check ball ? impact relief valve has a 150 psi ratio before it kicks in ?<br /><br />and lets hyd fluid bypass or backflow to resovoir <br />the slide valve must be a big part of it<br /><br />how does this apply to the reverse situation <br />instead of hitting a stump...?<br /><br />basicly what happens when you hit a stump...?<br /> <br />a vavle must go wow we just hit something<br />(i.e impact relief valve seems like the logical way to let the lower unit swing up and not rip your transom out<br />im i figurining it out or am i in the twilight zone<br /><br />thanks
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,471
Re: Power tilt/trim Reverse & Stumps question

tbarr, I have the same T/T system as was original for your motor. When you hit anything going forward, the motor will tilt up, hopefully without damage. I hit a telephone pole at 45MPH without damage. I hit a rock at 35 MPH, and it only broke off the skeg, which I thought was a bargain.<br /><br />The reverse lock knob when released, will allow you to tilt the motor by hand. I only used it during the winter, when the battery was disconnected and I wanted to tilt the motor up.<br /><br />If you hit something while in reverse, the T/T system is not going to give easily, since it has to be firm enough to maintain trim at full throttle in forward. I am always extra careful while in reverse.
 

wilde1j

Vice Admiral
Joined
Apr 15, 2002
Messages
5,964
Re: Power tilt/trim Reverse & Stumps question

You have zero protection in reverse. Your only help is DON'T HIT ANYTHING, bc if you do at any speed, something's going to break.<br /><br />In forward, the motor will kick up during a hard (or soft) hit when at planing speeds.
 

tbarr106

Recruit
Joined
Jul 20, 2004
Messages
5
Re: Power tilt/trim Reverse & Stumps question

hi <br />thanks for the info guys<br />my rams came in this week and im bidding on several pumps on ebay<br /><br />i see a lot of 2 port mercuiser pumps<br /><br />and some 4 port outboard pumps for my model<br />some with reverse lock some without<br /><br />im wondering if these pumps are rated for different hp mtrs ?do they have different PSI ratings for the smaller mtrs vs larger mtrs<br /><br />im buying a pump used ... has anyone rebuilt one?<br />was it a hassel or fairly simple ?<br /><br />ive rebuilt different type's of pumps with relative ease before<br />relace orings/ snap rings/seals/impellers /ball-check/ect.. clean and assemble ...<br /><br />ive been reading this forum on most common trim problems<br />seems the check balls and orings solenoids & elect mtr..are main culprits for pump failure<br /><br />or seals in rams..too<br /><br />are rebuild kits avail for valve body?<br /><br />seems a elect starter repair shop could rebuild the mtr/ brushes ect.. <br /><br />also.. im looking at a diag of the trim cly assembly and notice item 44 is a strap of some sort called a tilt stop part# a-63443<br />with a tube and pin also<br />i take it this is a restraining strap to limit tilt travel when trailering?<br /><br />one last ? i see lots of ad's for transom savers are they a piece that fits between the rams to stop mtr from bouncing and relieve pressure off rams ?<br /><br />any other tips on installing rams and pumps wiring is apreacited<br /><br />thanks <br />tbarr
 
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