[riv56]

I have a 1986 87? the power trim raises an lowers the motor but it will not hold, you can see the motor going down with your eye with no problem it goes down fast. My question is, is there a check valve in the system that should stop this problem, or maybe the cylinders need rebuilt. Any info you can give me would be appreciated. thanks

[hkeiner]

The attached thumbnail is the trim troubleshooting guide for my motor. Your trim design is probably different, but the guide may still be helpful to you.

Of course, the shop manual for your particular motor would provide better information to help you figure out what the cause(s) might be. it will also show you how to replace any defective parts. I suggest not messing with the trim without first having the manual on hand.

Good luck