Tilt troubles

[barcrusher]

I have a bafflng problem with my 2001 Yamaha F100 that I am hoping someone will have some ideas on.

I replaced the power tilt assembly, put everything back together and everything was working perfectly.

I noticed after a little while that the motor was slowly lowering under its own weight.

I took out the manual relief screw and noticed that the circlip which holds the spring and push rod had come out. Simple I thought - I replaced the relief screw and reassembled.

Now the tilt will not lift the motor up, or hold the motor under its own weight.

When I take the tilt unit off the boat, it goes up and down freely, and seems to have plenty of power, but as soon as it is put back onto the boat it doesn't have the power to lift the motor or hold it.

I have literally taken off every single nut/bolt/spring/valve on the unit and reassembled, and I am stumped.

I have thought it could be an air block but ive tried bleeding it to no avail.

Any suggestions would be much appreciated.

[pstephens46]

You replaced the entire assembly? A brand new unit? And then took it all apart again?

[barcrusher]

No, I replaced the cylinder which houses the pistons as the tilt piston was damaged

[99yam40]

any type of contamination can cause lots of trouble in those systems.
need a real clean room and special care to keep it all clean

[pstephens46]

Fairly complex. Lots of small parts, check balls and whatnot. Hard to point to one area of concern. You may have to find a pro. Even if you have to ship it somewhere.

[DennisG01]

No, I replaced the cylinder which houses the pistons as the tilt piston was damaged

If the tilt piston was damaged, why only replace the housing?

Between initially writing that you replaced the "assembly" (which infers "everything"... the entire thing) and this last statement, it's hard to udnerstand what you've done. Can you clear this up by being more specific/clearer in what you write?

Possibly you just didn't bleed it well enough - sometimes it takes quite a few times.