I own a 90hp 1988 Mercury outboard. I have the square type power trim and tilt motor. The motor works sometimes, but most of the time I have to tap on the lower unit or on the power trim and tilt motor to get it to move up or down. The solenoids will click and then I have to tap sometimes hard, sometimes gently and the motor moves up or down depending on which direction I have the switch in. Can someone help me with this diagnosis? I think it might be the brush card, brushes getting stuck, I hope its not a dead spot in the armature of the motor???? Also, is it necessary to remove the entire motor to get the power trim and tilt motor out? Help here, in detail would be much appreciated!
Hi Tadd, checked oil level and its full, can anyone tell me if the armature would be suspect? I do think it might be the brushes, but the brushes are NLA from Mercury so a starter/alternator rebuild place might be my best bet to repair these if they are worn???
On my 90hp motor, can someone tell me how to remove the top cross pin so I can take out the single ram on my motor? I cant pound it thru because Id have to pound from the backside, do I just drive the center pin this cross pin pushes into and shear it and replace it with a new cross pin????
I recently did a re&re on a 87 70hp. It is likely the same setup as yours. The pin was a real tricky job. I had the motor off the hull to get it out. But if your main goal is to re&re your trim pump motor, the way to do it is to leave the piston in place and remove one side of the main motor mount bracket (3 big bolts at the base and then undo the steering tube), and that will give you access to the screws that hold on the trim pump.
Dear DeepBlue, I know which bolts your talking about when removing to loosen up the power trim and tilt, but I also have to remove the two transom motor mount bolts also, right? I just want to remove the motor so I can get at the brush card to inspect the brushes and maybe take them into a motor rebuild shop to replace the brushes. The brush card is no longer available from Mercury. As far as the steering cable goes, there are only three bolts or nuts to remove, the steering tube nut, the retaining nut on the same threaded shaft as the steering tube nut and the arm nut on the opposite side of the motor?
One other thing DeepBlue, my cross pin does not have the button head on it, isn't this pin made to shear when the main pin is punched through? I also have to remove the trim tilt sending unit which is on the slotted end of the main pin on the opposite side of the motor.
You should not remove the pin. It may be that you can shear it off, but removal should not be necessary to remove the pump motor. Just remove the transom mount bracket on the pump side. Yes you will have to remove the 2 transom mount bolts, the 3 others, and the steering as you indicated. Then the entire mount on one side will move out of your way, giving you access to the pump motor. Mine did not have the trim sender, I dont know if you have to disconnect that or not, but I dont think you do.
When you pull the pump motor off, pay close attn to the the parts at the base, there is likely an o-ring, and a tiny driveshaft that will probably fall out if you are not watching closely.
I have a question, I tilted my outboard motor to the full tilt position and took it back down and it has worked super for the past couple days!? Not sure what happened!? I went out today, sucked out the old transmission fluid from the reservoir and refilled it with fresh fluid, ran it through a full tilt session and back down and then back to full tilt and rechecked the fluid. It seems to be working wonderfully now, I dont have to tap on the motor housing or the lower unit to get my trim motor to run. Anyone have any ideas why this worked?? Before the motor would only work sometimes and only move slowly at first until I ran it through a few cycles. Now it works superbly!? Could it have been the old ATF fluid in the oil tank for the trim and tilt?
Deepblue22 is absolutely correct in the procedure to best acces the trim pump and motor located on the starboard side. The brush card assy. can be purchased on ebay for under $20. at a "buy it now" price and then add shipping. This is a bargain due to the fact that most parts for these systems are no longer available and an aftermarket motor is around $300. . Once you get the parts and access the trim motor simply remove the four top cap retaining screws and replace the brush card assy. This will require you to cut the wires to the old one and solder the new one in. As a big time note remember that when you put the top cap screws back on not to over tighten them. Doing so puts to much pressure on the top cap bearing/bushing and prevents rotation of the unit. This can be quite the trial and error process as if too loose it does not rotatate properly either. Mine is a 1990 and I've been where you are. I recently purchased a complete used assy. on ebay for the next time around since part are getting so scarce. "Good Luck".
Thank you Kingfisher, if you know where on ebay I can get the brush card assembly for my power trim and tilt motor Id truly greatly appreciate your help. I have the Square motor, 3 wire design, 1988 motor, Serial # OB302485. Thank you so much!!!
I checked my saved ebay info thinking I had the store saved. No such luck. I came across it while searching ebay for a used trim system. It was in one of the hits that offered new parts and had a view sellers store. I sure idf you are patient and creative in your ebay search you will find it as I did.
I did some more looking around and ishopmarine.com has a brush and spring kit for $12.78. It would probably not be much more trouble to do each brush and spring over the card kit what with the soldering and all. Good Luck..
1988 Mercury Power Trim and Tilt
Linear Mode
