not the usual tilt and trim question

[winner2000]

have searched the archives and didn't see my problem covered,so i'll toss this out here. 1986 blackmax 200hp with 3 wire 3 ram tilt and trim. my tilt works fine and the trim cylinders raise up,but will not go back down. if i use the manual release valve,they retract and the unit tilts back up fine,but not so going down. full of fluid and color looks fine.any ideas where to start?

 

[guyjg]

...trim cylinders raise up,but will not go back down.

Does the trim motor run in the down movement of the throttle/shifter switch? Is there a remote switch on the engine? Does it move the engine up/down? If neither switch actuation causes the motor to run in the down mode swap trim relays to see if it won't raise the engine. If the relay swap changes the problem replace both relays.

 

[winner2000]

all the switches are fine,it raises and lowers motor full up and down until it hits the trim part of cycle and the motor runs but the trim rams don't retract. at thaat time i use the manual release and it glides on down and will trim up,hit tilt cycle and raise fully. goes down fine until it gets to the trim and stops retracting

 

[guyjg]

There is a valve in the valve body assy. that allows the trim rams to retract. Turning the manual release valve screw releases the pressure that the down valve should have done. I suggest you take it to someone with test equipment to verify the valve body has a problem.

 

[winner2000]

any guess as to what would make one suddenly go bad? are we talking about a relief valve? i have searched all day for a diagram of the path of the hydraulics to see where the blockage is with no luck

 

[guyjg]

I have searched all day for a diagram of the path of the hydraulics

It's included w/all Merc. factory engine manuals. If yours uses ATF instead of hydraulic oil you can try to drain some and add ATF conditioner/cleaner to it to see if it will clean the internals. I would call Mercury OB engineering and ask them what to do.