1990 TILT seal 70hp

[aaatom50]

I have a leak in the tilt seal area (not trim). I have removed the piston from the cylinder, and the impact valves from the piston, but I cannot figure out how to get the piston off the rod to replace the seals in the cap. I have done this procedure many times on Mercs and johnson/evinrude, do I just have to unscrew the piston , or is there a secret that I just bon't know about, like heating the piston?
thanks,
Tom

[aaatom50]

Answer found

Since I got no help from other members, I thought I'd post the answer to my own question. The piston did unscrew from the rod, which then allowed me to replace the seal in the cap, however the seal or as Yamaha calls it "ring, back up" (PN 6H1-43872-10-00) is the incorrect dust seal for this engine. I opted instead for a common grease type seal from the auto parts store with a S/S metal case and it works fine.

P.S. Thanks for the help!

[robert graham]

Thanks for the information regarding your tilt seals. Most folks, myself included, either don't or won't work on the tilt/trim units, since I believe they can be tough to work on. Also, the tilt/trim units don't seem to give much trouble from the mechanical/hydraulic side, but more from the electrical/motor/relays. Anyway, thanks again!

[200090tlry]

Yes you found one of my posts

Yep it will unscrew watch those springs and balls. Not tough it you have all proper tools for caps. SAve $1500 doing it yourself priceless