90TLRA tilt cylinder piston removal

[holmen78]

How do you take off the piston from the tilt shaft? I want to replace the oil seal in the cap and need to get the piston off.

Do I need to remove the spring dowel and unthread the piston? Spring dowel visible in picture.

[fairdeal]

lol that was my thought, too - but wrong. don't touch that roll pin.

just unscrew the piston from the shaft - std right-hand thread

Rodbolts' neat trick - hold top of shaft in vise, drop two 5/16" bolts/rods into a couple of the piston holes (from which you already carefully removed/contained the balls etc)
then use a rod between the bolts for leverage to unscrew the piston


see this thread:

http://www.yamahaoutboardparts.com/f...d-th27537.html

[holmen78]

Thanks a lot for advice. Of course I lost one ball somewhere, aargh. I’m going to test with a slightly bigger ball ( 3 hundreds of 1mm bigger) to see if it works. Hope it does.

[fairdeal]

Of course I lost one ball somewhere, aargh. I’m going to test with a slightly bigger ball ( 3 hundreds of 1mm bigger) to see if it works. Hope it does.

Bummer. I nearly had to scrounge up a substitute - then got lucky when the lost ball "showed back up".

but I felt confident that the valve design would be fairly tolerant of a difference in ball diameter.

[holmen78]

Yeah, I looked at the seat inside the piston where the ball is supposed to seal, and I can’t imagine a slightly bigger ball wouldn’t work. But I will search for an other hour for it, lol.

It was an excellent thread that was linked in the first answer.

[rodbolt17]

nope
you cannot randomly substitute check valves.
wont work and you will take it back apart to install the correct parts.

[holmen78]

The bad thing is the valve balls are not sold separately and I’m not going to pay $500 for a new tilt piston sub assy just because one steel ball is missing. I have no choice but to try with the 0.0011811 inch (0.03mm) bigger ball and hope it seats. According to local Yamaha service dealer even a 4mm ball will work, so keeping my fingers crossed

[boscoe99]

The bad thing is the valve balls are not sold separately and I’m not going to pay $500 for a new tilt piston sub assy just because one steel ball is missing. I have no choice but to try with the 0.0011811 inch (0.03mm) bigger ball and hope it seats. According to local Yamaha service dealer even a 4mm ball will work, so keeping my fingers crossed

If a dealer says it, it must be true.

I read this on the inner web.

[holmen78]

I will let you all know how it works out once I have received all the spare parts and assembled the ptt back on.

[holmen78]

Got new ball bearing balls for my tilt piston. Replaced the one I lost with the new one and everything is working normally. They where 0.02mm bigger than original. Actually the new balls where rated as 5/32” in diameter.

[TownsendsFJR1300]

Thanks for the update.

You may have saved someone mucho $ down the road...

.