Issue with power tilt/trim question for 78 Mercury 800...first time boat owner

mondakman

Recruit
Joined
Mar 5, 2016
Messages
3
Hey everybody! As my title says, this is my first time owning a powerboat, but I've been a long time reader of iboats forums. I love the website, so helpful. I recently purchased a good for the year condition 1979 Starcraft Supersport, with a 1978 Mercury 800 Thunderbolt outboard. Brought it home, and I'm having issues with the power tilt. The tilt won't go down. The motor for the power tilt sounds like it is running correctly and the outboard sounds and creaks like it wants to go down, but it won't move, almost like something is holding it in place. However, when I push the motor down a little bit and then hit the up button, the tilt pulls it back up. I read the other forums with similar issues and drained the fluid in the cylinders and a bit from the reservoir, closed them back up, and then topped the reservoir off to replace what I had drained. That didn't do the trick, though. I disengaged/reengaged the lock on the tilt/trim unit itself and tried to lower, which didn't help. I'm pretty sure I unlocked/relocked the L shaped trim lock on the outboard by moving it back and forth and then hitting the lower button, but that didn't help either. I don't see anything else that could be locking the motor in the up position. I'm not sure if I'm doing something wrong, or if I'm missing something. Anyone have any ideas of what to try? or any advice if I'm doing something wrong? I'd like to keep it away from the mechanics, if possible...college kid and don't have a ton of money...at least when the marinas here in NoDak are charging $115 an hour! Also, where's the trim lock so I could lower it manually, if necessary. Thanks, I appreciate all the help!
 

mondakman

Recruit
Joined
Mar 5, 2016
Messages
3
Just as an update, I had the previous owner call me back and say he'd had issues with it, as well, and that manually lowering and raising it a couple times should do the trick just to get it going. It did. So simple. I cannot for the life of me figure out how to delete this thread, though, so if anyone has any advice on that, that'd be great so that my hopefully answered question isn't cluttering up the topic board. Thanks and keep up the good work.
 

fhhuber

Lieutenant
Joined
Jun 19, 2014
Messages
1,365
Check and see if the mechanical latch is causing your issue. Without power tilt/trim the engine uses a spring loaded latch to keep it down in reverse. If that locks in the power can't raise the motor.

could be as simple as something (that should have been deleted when the power tilt went on) having a bad spring.
 

merc850

Commander
Joined
Jul 7, 2010
Messages
2,022
Have you bled the system? also take the lower mount bushings and out and grease them and check to see that the tilt bracket is moving freely. I think there are grease fittings on it too.

trimpump.jpg power-trim-bleedingsmall.jpg
 
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