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Adding Tilt & Trim to a '89 50hp 507Y9B

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  • Adding Tilt & Trim to a '89 50hp 507Y9B

    I'm preparing to restore and install an e-Bay purchased tilt and trim system on my 50HP. I used to maintain and repair US, Swiss and Japanese printing presses and all of their associated electronic, hydraulic, pneumatic and mechanical components so I feel I have at least a glimmer of chance to succeed with this rebuilt/install.

    I would first like to identify if I really purchased the correct TnT system. The seller assured me this was so. Sigh.

    My motor is a Force, 50hp, model #507Y9B, serial #1561.

    I purchased a two wire, non-relayed, external pump, integral trim and separate tilt cylinder system, as is but functioning. The seller listed the unit as coming from a 40hp, year unidentified. He said "We ran this unit and it ran smooth and quite,we saw no leaks,in the rams or fittings. It Easily lifted the motor. The fill plug on the reservoir is stripped so it can leak there without some tread tape, this does not affect usage."

    I have restored many damaged threads in castings before and intend to use Loctite 37390 Form-A-Thread stripped thread repair kit as the fill plug is a low pressure fluid fitting.

    Picture of unit:


    Could someone help me verify that I have the correct unit? (RITT?) and how to identify what the part numbers for the individual sub assemblies are so I can start acquiring the proper seals, o-rings and lubricants prior to disassembling this "puppy".

    I have a copy of Apple Rubber Product's "Seal Design Guide" and am familiar with selecting reciprocating seals using standard AS 568A o-rings. As I will be using this motor in fresh water I think that Buna-N or Nitrile o-rings should be acceptable unless someone sees a special requirement for Viton o-rings.

    This is my first post after having mined this forum for the last several weeks and I want to compliment the moderators and members for creating such a wonderful and valuable resource.

    Thank you - Chris

  • #2
    Re: Adding Tilt & Trim to a '89 50hp 507Y9B

    Your picture doesn't work.

    However, I think the correct unit for your engine will look like this:

    use urethane on any seal that is completely or partially exposed to either air, sun, or water. Use viton on any seal that might be exposed to ATF or regular motor oil additives or is less than 1/16" in diameter. Buna is fine for everything else. Do not use square rings where there was originally round and do not use round where originally square (aka die cut). You may use quad rings for tilt piston ring, tilt piston shaft to top head, trim piston shaft to cover, and valve body shuttle.

    the only way to get a lot of the seals is by trial and error. It took me about 3 months to identify and locate the exactly right parts my first time. To the best of my knowledge there aren't any shortcuts without a corresponding drop in quality.

    to repair a striped fill plug on plastic reservoir - tap it out to 7/16" and use a short stainless bolt. Fit an oring around the shaft of bolt. It only needs to be tightened enough to keep water out of oil. Generally speaking mild finger-tight is perfect. The oring will keep it from vibrating out.


    • #3
      Re: Adding Tilt & Trim to a '89 50hp 507Y9B

      Thank you, RITT

      I'm sorry the path-name came through instead of the image. I upped my editor to "Advanced" hoping it would resolve - No Joy
      Here is the URL for the item on e-bay.


      It looks to be the same except for the decrepitude and a funky paint job. My 50hp motor is black so I'll resolve that in the process of restoration.

      What material hardness do you recommend or rather, what pressure is experienced by the piston and valve o-rings. IE. Would you recommend 75D (Shore A)?

      Thanks again - Chris


      • #4
        Re: Adding Tilt & Trim to a '89 50hp 507Y9B

        I don't think you will have the luxury of being picky when doing just one system. If you can find right size in a high quality product and they will sell you less than 100 .. then that is the right hardness to use.

        I actually saw the stainless retaining clips in a local hardware store once. You may think that $2.50 each is a lot to pay for that clip. But, if you do buy them wholesale then what are you going to do with the other 98?


        • #5
          Re: Adding Tilt & Trim to a '89 50hp 507Y9B

          Looking at the picture on E-Bay, it looks like the motor/valve body has been rewelded to the ataching bracket. Make sure it's a good weld and won't be coming apart in the near future. Another thing, I may be wrong here but it looks like the trim cylinder is junk. That should be extended all the way out when the motor is tilted out like it is in the picture. At least that's the way it is on mine.

          I just took mine apart after getting fed up with the leaking down in both cylinders. At first I just rebuilt the valve body but I still had problems. Next came the tilt cylinder and when that didn't cure my problem, I ended up doing the trim cylinder. When I got done with the trim cylinder, I had finally got that to stop bleeding down. But the tilt cylinder still bled down. So, I took the valve body back apart and replaced the o-rings again and now(so far) it's holding up real well.

          All the o-rings I used were standard sizes and I just matched them up. Unfortunatly, I didn't write any sizes down so I can't help you there.



          • #6
            Re: Adding Tilt & Trim to a '89 50hp 507Y9B

            you picked a risky one to rebuild. The tilt ram top head might not be repairable. About one third of the rams with rubber boot use a seal that can't be replaced. About one fourth of the systems using the rubber boot also use a type of manual release valve that can't be repaired. The good news is that both of these items last longer than the rebuildable versions. The bad news is that it adds anywhere from $30 to $200 to the cost of rebuilding.

            I think you should see if it works and then either sell it or use it - as is. If you do sell it then look for a system with 2w motor.


            • #7
              Re: Adding Tilt & Trim to a '89 50hp 507Y9B

              Thanks Brian & RRitt,

              OK, so I did some things right and I did some things not so right. Par for my course.

              As far as being able to be picky about acquiring small quantities of specialized or exotic o-rings, I have some avenues that I can pursue. I have a fairly large personal design selection of Buna-N (Nitrile) Shore A 70 durometer o-rings and a smaller selection of Shore A 75 & 90 Viton o-rings in the basement. McMaster-Carr does sell a very nice maintenance set of both Buna-N and Viton o-rings in an plastic case organizer. I'll admit that $20 to 90 for a set might be a bit stiff if you are only going to use it once. I don't have that problem. RRitt, have you ever purchased o-rings from Marco Rubber and Plastic Products?

              I have found that many of the smaller, and some of the larger suppliers will provide 1 to 10 quantities of the odder sized o-rings if you request a design sample and offer to pay their S&H and any standard engineering sample fee. More often than not I have received the sample at little or no cost. The ethical issue is to ensure that you explain the items are for your personal use so the salesman is not mislead into expecting a large order down the line. I have found that honesty is the best door opener.

              I am determined to restore this assemblage. Call it a "Challange."

              I retired some 9 years ago from a postion, with a large defense contractor, as the lead mechanical designer and mentor for young engineers and designers working in a MILSPEC environment. I taught by the "touchy-feelie" hands on method. How can you properly design something if you have no understanding of the manufacturing process? I can't tell you how many young engineers (some with a Master's degree) I've met who had never tapped a hole in their lives. Yet there they were designing a machine with MILSPEC threading or Helicoils. One gentleman actually asked me how you pressed a Helicoil into the aluminum! I marched him down to the lab and had him tap ten or so holes and install ST inserts in them. I had him do this until his work passed MILSPEC final inspection criteria. I do miss my job, I loved it. I'll have to say though, that it's nice not having to get up at 4:00 AM every morning but one to beat the traffic and younger crowd so I could set up a morning's instruction or advance a design. (sorry - Get off Soap Box)

              Yes, The bracket has been welded to repair an earlier break. Although the weld appears to be of good quality I had planned to make a new additional two piece bracket from some leftover aluminum, 1/4" & 3/8" thick, plate to mount on the starboard stern bracket that will clamp around the top diameter of the TnT electric motor and rigidify this attachment point. I will attach the new bracket to the stern bracket using the pivot hole that is emptied after removing the STOP-TILT-STBD plate (item 42 on the Swivel Bracket and Stern Brackets exploded assembly drawing). This will give me an excuse to use that new spool gun I got for my Lincoln 180C welder last year.

              I'll report my progress.

              Can anyone tell me through a private message stream just what I'm doing wrong in inserting my images?

              Thanks, Chris


              • #8
                Re: Adding Tilt & Trim to a '89 50hp 507Y9B

                IMO, if you can sell the unit for nearly what you paid, then you should. Once you open up the rams & motor to rebuild it then there is no turning back. Find a 2w system. It has fewer potential dead ends. The welded bracket isn't the best start ever. So ... if it works then sell it and buy the one listed for your year and engine (2 wire).


                • #9
                  Re: Adding Tilt & Trim to a '89 50hp 507Y9B

                  Hi RRitt,

                  I went out today to test the TnT unit and discovered that the reason the trim piston is retracted when the tilt piston is extended is ... that the S/S input and output tubing for the trim valve are reversed. A visual X crossover.

                  This unit has three wires attached to the motor but no relays. The up/down switch is a single pole/double throw momentary action spring loaded center return normally open and was included with the unit. After hooking it up to a wheel chair battery I tested the unit for gross function. It does work. The fluid is red which might indicate that it is ATF instead of SAE 10W40 oil as my Chilton manual recommends.

                  The main problem I see with the entire deal is that there in no manual release spindle screw slot where there IMHO should be one. The casting on the front of the motor/pump assembly is labeled "Manual Release" but there is just a blank metal plate under the retaining ring in the cavity where the Manual Release spool should be. Is it common to not have a manual release?

                  If the manual release is supposed to be there, I will contact e-Bay to return the system as the description did not state that the units function was impaired or missing parts.

                  Do you concur? I anything ever easy?

                  Thanks, Chris


                  • #10
                    Sign up today
                    Re: Adding Tilt & Trim to a '89 50hp 507Y9B

                    There really is no manual release on this model. You remove the retaining clip. Some critical parts often end up on the bottom of lake but your motor does come down. A more suitable label would have been emergency release.

                    The trim-up port is the one that faces straight down. The trim down port is the next to last side port. There is no such thing as a simple crossing of these two tubes. The tube nuts don't even point in same direction. Somebody went to a lot of trouble to hook it up that way. Which also means ... you are at very high risk of stripped threads. So be careful about that too.

                    If you are trying to find a valid reason for return (a wise choice if available) then I see three avenues. First it was advertised as a working trim and tilt. It is not. Even if every individual part works perfectly it will not trim with the two oil tubes reversed. Second, no mention was made of the broken and welded mounting base. Is the weld as good as original metal? Third, it simply isn't the system intended for your year. It works, yes, but will not be the system to show up in parts diagrams. The third option is probably the worst one because pleading buyer mistake might result in restocking fees.