Different Trim Problem on Mercury 115 Tracker

I have a 1995 (or 1996) Mercury 115 Tracker outboard. I have searched the board for this answer and I did not see it. My trim on land and at idle will trim up and down with no problem. However, while under way the motor will not trim up. (It tries but the motor just starts bouncing)If I stop and trim and then go, it SEEMS to stay trimmed up. I am in the process of doing a overnight test.<br /><br /> I checked the fluid and when I unscrewed the big flat head screw at the bottom of the pump it had oil. Just in case I put more in until it was pouring out. I am in the dark here. I am thinking either 1)need to bleed the cylinder 2)I am adding fluid wrong or 3) my trim motor has seen better days and I about to shell out some serious clams.<br /><br /> It seems that 90% of the trim problems on here are electrical, which is understandable given electricity is a pain. However, mine seems to be a trim problem while under load. I think my motor is just weak on its way out but I am praying it is a solenoid <br /><br />Thanks in advance for any help.<br /><br />Brad

Re: Different Trim Problem on Mercury 115 Tracker

Welcome to iboats. <br /><br />It's not a relay. It's hydraulic and it may be normal. There is a trim range and there is a tilt range. The motor won't hold position in the tilt range when there's forward thrust. That's to protect the water pump by preventing the intakes from coming out of the water. It's also for control since a radically trimmed motor can have severe consequences if you're not awfuly careful. If you're having this trouble down in the trim range, then you have an internal hydraulic problem in the unit. Otherwise it's behaving as it was designed.

Re: Different Trim Problem on Mercury 115 Tracker

Thanks for the input.<br /><br />I think it is in the trim range because it started doing this 2 weeks ago. (Nothing I know of changed to cause this) What are some of the internal hydraulic problems you can have that cause this? Valves? Clogged hoses? Seals? Scarred Piston?<br /><br />Thanks, <br />Brad

Re: Different Trim Problem on Mercury 115 Tracker

I have pin pointed the problem. <br /><br />I need a trim piston rebuild kit. Mercury does not sell them anymore, any idea where I can get one?

Re: Different Trim Problem on Mercury 115 Tracker

Problem solved. I threw in the towel and brought the boat to a shop. They found a seal kit from a different manufacuter that fit. Total cost for rebuilt ram and pump : ~$400.<br /><br />Thank you for all of your help.