1999 Yamaha F100 trim and tilt having trouble going down

[amlorenz]

Hello all, I am new to this site and really appreciate any info you can give me before I haul my boat to the shop.

I have a 1999 Yamaha F100 outboard. The problem I am having is with the trim and tilt assembly. The motor will go up just fine but when I go to the put the motor down, It seems to lock up. I then have to "jog" the motor up slightly. The motor then goes down just fine. If I have the motor in the full up position, it will not go down at all since I am not able to put the motor up a little first. I then have to use the manual release to lower the motor slightly which it then works ok.

I was told by one shop that it is a faulty seal within the assembly and im lookin at about $200 to have them fix it. Any suggestions? Thank you.

[boats.net]

It needs both the main valves replaced with new style valve, part number 67F-43802-00-00
It's number 50 in this diagram Yamaha Outboard Parts 1999 F100TLRX POWER TRIM & TILT ASSEMBLY 1 Diagram

[amlorenz]

Excellent. From the looks of the diagram this looks like something that I could do. Can I access those parts without taking the whole pump apart?

[amlorenz]

Also, am I looking at the diagram correctly in that I simply unscrew the old valves and replace them with the new ones? Or is there more to it than that? I ordered the valves already so just am kind of wondering how labor intensive this will be. Thank you again very much for the advice.

[amlorenz]

Has anyone else done this that could give me some insight? Thanks

[boats.net]

You will need to remove power trim unit from motor, one main valve is in back. Lay it on bench and remove main valve(that will keep piston from falling out) and install new one, turn it over replace other main valve.

[amlorenz]

got the valves this morning and took about 20 min to replace them. Trim works great. Thanks for the help!

[mattw92]

Boats.net,

I'm sorry to hijack this thread but I'm having the exact same problem. You said...

"You will need to remove power trim unit from motor, one main valve is in back. Lay it on bench and remove main valve(that will keep piston from falling out) and install new one, turn it over replace other main valve."

Also, above, you said...

"It's number 50 in this diagram Yamaha Outboard Parts 1999 F100TLRX POWER TRIM & TILT ASSEMBLY 1 Diagram"

You reference one part but said it needs to be replaced "on both sides". Do I order 2 of part #50? Where in the diagram does the 2nd one go? I apologize for not seeing it but I've looked the diagram over a few times.

Also, because I've been having this problem for a while, I've been using my release screw (part #68) every couple of months. It's close to stripping out the head (where the flat blade goes), so I am going to replace that at the same time (it's already to the point I can't get it to loosen up; any tips for getting it out?)

Will I lose any hydraulic fluid pulling any of these parts out? If so, how much and what part number should I use?

I appreciate any help.

Matt

[boats.net]

Matt
If you have the same model motor then order 2 of number 50 in diagram, the second one is in back power trim unit just opposite of front one. You may loose fluid, recheck fluid level after it is reassembled.

[mattw92]

Thank you. I did double-check and it's the F100TLRX, so same model motor. I have the parts in my cart and will be ordering them in a minute. I unhooked the shock pins tonight but it looks like the PTT unit is hard-wired in. To get this on a bench, do I just unbolt the PTT motor from the PTT unit and let it stay with the boat (I'll tie it up, of course, so it's not hanging by the electrical wires). Or, is there a different way to unhook the electrical wires?

Again, appreciate the help!

Matt

[boats.net]

Disconnect wires from trim relay on engine and leave power trim togather.

[mattw92]

Thanks, worked perfectly! It was a little time consuming snaking the wires out of the motor once I unhooked them from the relay (15 minutes or so) but the parts were easy to replace and, thankfully, just finished a week-long trip in Canada with the boat and the PTT performed flawlessly!

If anyone is having this same problem, I recommend replacing these parts. Thanks for the help!

[Rob 829]

F100.trouble coming down after max tilt

I am from the Netherlands.
I have got one F100 aswell with the same problem.
I order the new valves and replaced then for the old one.
It works !!
Thank you

Greetings from Holland