1990 Force 90HP Tilt & Trim

[irnman1827]

Hi,<br /><br />Hope this all make sense.<br />I am having problems with my tilt & trim system this year. The system worked OK last year, but did settle some. This year, first time on the water, I was fishing w/ the motor raised (and off) and I heard a couple of fairly loud "pops" from the direction of the motor. The motor did settle. However the motor would no longer lift. Upon closer inspection, 3 of 5 bolt heads were broken off on the trim cylinder and it was leaking fluid. I removed the trim cylinder and the actual cylinder was skewed, not allowing the piston to move. I was able to get the cylinder straightened so the piston would move properly. I put the trim cylinder back together and the trim portion seems to be functioning fine. Now the tilt will not lift the motor. There does not appear to be any fluid leaks and seems to have bled the air out. I removed the tilt cylinder from the motor and it functions properly without the weight of the motor. Any ideas why the tilt will not function under a load?<br /><br />Thanks alot,<br /><br />Jeff

 

[RRitt]

Re: 1990 Force 90HP Tilt & Trim

if you can get the tilt and trim cylinders off the boat then you should just rebuild the whole system and be done with it. If the five bolts holding the trim cover in place and the trim cylinder sleeve come out easily then you are looking at a very easy repair.<br />o-rings @ $15<br />oil seal @ $4<br />motor brushes and springs @ $12<br />SS studs for motor @ $5<br />shock eye bushings @ $8<br /><br />It would take about 4 hours without de-rusting and painting. 6-8hours with the cosmetics.<br /><br />but - back to your problem. with the shock and tilt removed does the motor lift easily? You should be able to tilt the motor fully with just one hand. If it does not tilt easily then check the carriage bolt that goes through front of stern brackets. This is your hinge point. Maybe it needs a healthy dose of wd-40. maybe the whole engine mount/swivel/tilt/steering is due for a good lube? if it does tilt easily, then there are only three suspects - <br />1) malfuntioning shock <br />2) malfunctioning tilt ram <br />3) malfunctioning pump (it takes less motor to pump torque to trim an idling motor than to tilt it)

 

[RRitt]

Re: 1990 Force 90HP Tilt & Trim

hmm ... my description of suspect #3 sounds confusing. let me try again.<br /><br />the trim piston is bigger than the tilt piston. It also has a much better fulcrum point. The reason is because the motor pushes against trim when you are moving. When you are not in gear it hardly takes any pressure at all for the trim to lift the engine. Specifically, a weak pump might be able to lift the trim piston but not have enough juice to lift the tilt.

 

[irnman1827]

Re: 1990 Force 90HP Tilt & Trim

Hi,<br /><br />Thanks for the reply. Tonight I removed the bolt that goes through the shock and the tilt cylinder. I was able to lift the motor OK. I was also able to move the shock up and down. I then removed the tilt cylinder and replaced all of the O-rings. The tilt cylinder did seem to perform better in my hands after I replaced the O-rings. I re-installed the tilt cylinder and I am having the same problem. I cannot raise the motor and if I manually raise the motor, the tilt/trim system will not hold the motor up. Could there be a valve somewhere that is not functioning properly? I am not all that familiar with the tilt/trim system.<br /><br />Thanks for your help,<br /><br />Jeff

 

[RRitt]

Re: 1990 Force 90HP Tilt & Trim

is your resevoir full? did you use appropriate fluid? It should be either non-detergent 30w (oil) or automatic transmission fluid (red fluid).<br /><br />If yes, then it is either pump or motor. Pump is doubtful if your system has never gotten water on the inside. weak motor can lift trim but not tilt.<br /><br />if pump seems to be turning normal then try cheap fix fist. get some inverted flare plugs or caps from NAPA. take loose oil lines. drain system and refill with mineral spirits. plug tilt fittings and thoroughly flush trim. unplug tilt and plug trim. throughly flush tilt. drain MS and refill with non-detergent oil or ATF. flush out mineral spirit residue. put back together and see if it works.

 

[irnman1827]

Re: 1990 Force 90HP Tilt & Trim

My reservoir was full, and I used tilt and trim fluid. I did pull the trim motor off this weekend. I separated the motor and pump. I disassembled the pump, which probably wasn't my best move, as I'm not sure exactly where the 4 BB's and 2 springs go. I couldn't see anything obviously wrong with the pump. It is strange that at the base of the two "posts" in the casting, there are holes. Also, there was a long set screw and nut in one of the posts, but nothing in the 2nd post, but the 2nd post is threaded. Not sure if this makes sense. The posts I am referring to are part of the casting and are about 2" high.<br /><br />Are there any aftermarket pumps and motors available for this system (just incase I've screwed this one up)? <br /><br />Thanks,<br /><br />Jeff

 

[RRitt]

Re: 1990 Force 90HP Tilt & Trim

I don't know what to tell you now. you shouldn't have taken it apart. the only reason for a pump to break is water causing rust or someone taking it apart.<br /><br />maybe you have twin engines?<br />then you can very, very, very carefully take the other one apart in order to see where the ball bearings & springs are supposed to go. squeeze it tightly as you remove the bolts. then very carefully and slowly lift the top off (while holding it over a baking pan). use a light coating of marine grease or vaseline to hold them in place during re-assembly.<br /><br />if it's shot, then try looking here through iboats for a rebuilt valve body. if you can find a PT116 motor then the valve should be somewhere close.

 

[irnman1827]

Re: 1990 Force 90HP Tilt & Trim

I don't think reassembly will be a problem if I know where the components go. I didn't think the trim motor was a problem because the outboard would not stay up. If the tilt and trim cylinders are OK, wouldn't the pump being bad be the only reason why the motor wouldn't stay up? The system is not holding pressure, as the outboard will not stay up. As you said, if the fluid is full and correct, then the motor or pump is the problem. The trim motor itself would not cause the outboard to fall. There is a loss of pressure somewhere. I've seen some pictures of the pump, and there were set screws in both of the "posts". There is a set screw in only one of mine. I also think the holes in the casting seem abnormal. Any thoughts?<br /><br />Thanks.

 

[RRitt]

Re: 1990 Force 90HP Tilt & Trim

IF the tilt cylinder is okay. That's a much bigger IF than the pump valve.<br /><br />get a female inverted flare cap from napa. should be less than a dollar. run the tilt up and block it so that it stays up. take the fitting loose from valve body that feeds bottom of tilt ram. cap it securely. remove blocks and see if you still have bleed down. if yes, then tilt cylinder. if no, then valve.<br /><br />they come in all flavors. one post, two post, no post. if something came loose, then it would have been inside your resevoir. if there was nothing but oil in your resevoir, then nothing came loose.

 

[irnman1827]

Re: 1990 Force 90HP Tilt & Trim

Thanks, I will try that.