84 Yammy 115 Tilt and Trim

[smoedog]

I've got said motor with hydro tilt and trim. Looks to have 3 cylinders. 2 for tilt and when them reach max extension the 3rd takes over for tilt.

I work Hydraulics in the air force so this is nothing new to me. But, not sure on how the pump works. Is there actually a solenoid valve that ports fluid from raise - neutral - lower, or is the raising and lowering controlled via the motor and which way it spins.

That being said here is my problem.

Underway I can not trim the motor up. But at a stand still I can trim it up no problem. After 30 mins or so, it will go from full up and bleed back down to full down. So I'm thinking its not a bypassing actuator since all 3 actuators would have to be bypassing.

So is there a rebuild kit? If not is it a solenoid valve that controls it, because if so, I can get seals without a problem. But if its the direction of the pump that controls flow, it might be harder.

 

[Capt Ken]

Re: 84 Yammy 115 Tilt and Trim

The motor is reversible thus changing direction of the fluid flow. Uses a shuttle to swap from one fluid direction to the other.

 

[smoedog]

Re: 84 Yammy 115 Tilt and Trim

Cool, so the shuttle valve could be bypassing. Do they sell seal kits? Seems like a pain to have to order seals individually

 

[robert graham]

Re: 84 Yammy 115 Tilt and Trim

I believe they're fairly complex and challenging to rebuild, and any first-timer would have a learning curve. But that said, a Yamaha Shop Manual for your specific motor would be the best place to begin. There will be some special tools and expertise required, but good luck and hope it goes well!

 

[grid]

Re: 84 Yammy 115 Tilt and Trim

You definitely don't want to get involved in a rebuild! Since many times the "shuttle" spool sticks in the system, what I've had to resort to is completely removing the manual release valve and dumping the oil. Be careful, and use the tilt locks to keep the engine up on the brackets. Watch your eyes, too. (That's a neat trick, watching your eyes...a mirror helps?) Anyway, make sure the o-rings on the valve are in good shape. Reinstall the valve, and add a mix of Dexron 3 transmission oil and Marvel Mystery Oil to the reservoir, running the tilt up and down until all the air is purged. I've had about a 75% success rate, which I think is good, but the other 25% of the customers are still peeved.

 

[smoedog]

Re: 84 Yammy 115 Tilt and Trim

I believe they're fairly complex and challenging to rebuild, and any first-timer would have a learning curve. But that said, a Yamaha Shop Manual for your specific motor would be the best place to begin. There will be some special tools and expertise required, but good luck and hope it goes well!

Actually, I realized I downloaded the manual I while back. It covers all this.

Looked at the tear down and schematics and looks easy.

 

[Capt Ken]

Re: 84 Yammy 115 Tilt and Trim

No so called rebuild kits. You have to order each seal and Oring.

 

[robert graham]

Re: 84 Yammy 115 Tilt and Trim

Actually, I realized I downloaded the manual I while back. It covers all this.

Looked at the tear down and schematics and looks easy.

Well, good luck....with your hydraulics experience and training, hopefully it goes well. Keep us posted with your progress!