power tilt and trim problem

[bouncer]

I have 2 40hp mecury outboards 1997 models the power tilt works fine up down ,,,,,,if i leave it up over night ,it holds and does not creep down

But the problem is when the boat is under power the motor trims in untill motor hits the tabs and it wont trim out at all .....untill the boat is not under power any more....

can any one help me with this problem please it used to be ok


thanks


bouncer

[boats.net]

Some of the smaller hp motors had a power tilt system which was tilt only and not trim. If it is a power tilt and trim then it may have a valve not seating in valve body. Check the serial number to see if it has tilt and trim.

[bouncer]

Thanks for the reply i have been still investergating my problem further ,,,,,, on my power tilt has both trim and tilt ,,,,the tilt is ok its the trim which is the problem ,,,,,,, it used to work ok ,,,, but the prob has occurred on both motors now it was only one to start with ,,,,,but now itds both ,,,, it has been suggested that i drain the old oil out do a fluse with new oil should i try that first ,,,,,deos any one have any other ideas on my problem ,,,,,,,



thanks bouncer

[robert j f]

I would at the very least inspect the fluid. Be sure its not water contaminated, or pardon the spelling aeriated, appearing to have bubbles after operating. If you do see contamination or milky looking fluid, flushing would be good and beneficial but thats not to say it wont happen again because of a bad seal thats letting the moisture in. Hope this helps also if it appears to have bubbles in it you might have a small piece of oring stuck in an orifice within the system