Tilt Cylinder Leak - Tilt Tube Movement OX66 250. Rodbolt got any input?

[steamin53]

The engine is a TXRX250 (1999 model) used in the Gulf of Mexico. I'm the second owner. I've been good about lube of the grease fittings but there's no telling how it might have been cared for prior to my buying it.

The problem is that I've had a leak in the tilt cylinder hydraulics. I had a Yamaha dealer replace the seals and the cap but the leak began almost again almost immediately. As I recall it leaks in both the up and down movements. The dealer found a slight scratch in the ram which he polished out. That area only contacts the wiper seal in the cap which if I'm correct does not have any hydraulic pressure on it.

I note that there is significant movement of the motor for and aft which appears to be at the tilt tube. My guess is that the movement fore and aft is causing the tilt piston in the tilt cylinder to rock slightly in the cylinder causing displacement of the seals and probably rocking the ram against the wiper seal as well. It may even have caused the scratch (only on one side) of the ram rod.

I wonder if replacement of the tube and or bushings might fix the problem.

Any suggestions?

[boscoe99]

The engine is a TXRX250 (1999 model) used in the Gulf of Mexico. I'm the second owner. I've been good about lube of the grease fittings but there's no telling how it might have been cared for prior to my buying it.

The problem is that I've had a leak in the tilt cylinder hydraulics. I had a Yamaha dealer replace the seals and the cap but the leak began almost again almost immediately. As I recall it leaks in both the up and down movements. The dealer found a slight scratch in the ram which he polished out. That area only contacts the wiper seal in the cap which if I'm correct does not have any hydraulic pressure on it.

I note that there is significant movement of the motor for and aft which appears to be at the tilt tube. My guess is that the movement fore and aft is causing the tilt piston in the tilt cylinder to rock slightly in the cylinder causing displacement of the seals and probably rocking the ram against the wiper seal as well. It may even have caused the scratch (only on one side) of the ram rod.

I wonder if replacement of the tube and or bushings might fix the problem.

Any suggestions?

The tilt and trim cylinders all have hydraulic pressure on them when the motor is tilted/trimmed upward or downward. There is an O ring in the cap that is supposed to keep hydraulic fluid in the cylinder. If hydraulic fluid gets past that seal then it will weep out via the dust seal. The fact that your tilt piston rod has/had a scratch on it would leave me to suspect that to be the source of the problem. But...

What did the old wiper seal and O ring look like when they were removed?

It is normal for even a brand new Yamaha to rock like crazy when it is in the UP tilt position by the way.

[steamin53]

Thanks for the response. All I can say about the seals is that they weren't torn. It's tough to assess the damage to the seal after they've been extracted with a pick.

We did of course install the new seals into a new cap and discarded the old one because someone had used the punch and hammer method to remove it prior to my acquiring the engine.

The scratch on the ram wasn't very significant in depth and to my thinking was rather odd to have been inflicted on it in the first place. I just don't see how it could have been scratched unless it had been from the rocking effect of the engine moving fore and aft in the bracket causing the ram to rock with it while the cylinder remained relatively stationary. For what it's worth I trailer this boat from N Alabama to Pensacola and use one of the "My Wedge" devices on a trim piston ram to protect the transom. There's no telling what the original owner used, if anything.

It would seem to me that in the "up mode" the hydraulic pressure is below the piston and that that area above the piston would be rather low as it is being displaced back to the reservoir but even at that it still leaks profusely. Probably worst I would guess (can't really recall) in the "down mode".

As a point of reference I also own a Yamaha 115 on another boat that rocks too... but nothing like the 250 we're talking about.

What's involved in replacing the tilt tube and bushings? Would it possibly be the cure for some or all of the movement issues? Where is the wear causing increased movement likely to have occurred; to the tube or to the bracket?

Any suggestions.

[rodbolt17]

there is a lot of motion on the tilt anchor pin and the tilt tube when tilted up.

I doubt that is causing the leak.

most likely something is scared,scuffed or burred.